Category Archives: Heaters

Best 10 Gallon Aquarium Heater

The standard 10 gallon aquarium is where many of us start our aquarist lives. Compact yet plenty of room to see our little buddies swimming around. To keep them safe we need the best 10 gallon aquarium heater we can find. Seeing how every brand has at least one heater the good are lost among the crowd. After all my years of fish keeping these models have proven their worth and will make your 10 gallon tank thrive!

In a rush? Skip to the Eheim Jager to be amazed.

Aquatop Quartz

Aquatop is my go to choice for low cost aquarium heaters.

Cost: Low
Warranty: 6 Months
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  • Consistent Temperature*
  • Easy To Read
  • Low Cost
  • Fully Submersible


  • Runs 2 Degrees Hot
  • Not Exact Settings
  • Fragile
  • Hard To Turn Knob

The Aquatop Quartz 50 watt comes in at 8.5″ x 1.25″. The heat will run consistently 2 degrees warmer than it is set to, making it reliable when properly set. By using a second thermometer you can easily find the right setting for your tank.

The main yet minor issue the Aquatop has is setting the heat. The dial on top of the heater is difficult to turn, especially when wet. However once it is set correctly you don’t need to worry about the settings being changed on accident.

The light/heating element on the Aquatop comes on for one minute intervals to ensure the water is not heated too quickly. This is a key feature many heaters miss when it comes to heating 10 gallon fish tanks.

One of the bigger draw backs this low cost 10 gallon aquarium heater has is the fragile design. While the glass is shatter resistant it is nowhere near shatter proof. Take caution when moving the heater around rocks or to the sink for cleaning. Holding the cord when walking to the sink was how I cracked my first heater.

Lifetime & Warranty

Aquatop offers a 6 month warranty, which is mostly used to catch the defective products. Keep an eye out for rusting metal coils and cracking glass. Contact the manufacturer immediately if you notice these.

On average the Aquatop 10 gallon aquarium heater will last 1-3 years. For the low cost the lifetime is pretty long and can even be more efficient than pricey heaters over the long run. Just be sure to treat the heater gently.

Marineland Precision Heater 50 Watt

Low cost with a lifetime warranty, Marineland makes it easy to get into the aquarium hobby.

Cost: Low
Warranty: Lifetime
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  • 1 Degree Increments
  • Easy To Read
  • Lifetime Warranty
  • Efficient Heating
  • Handy Mounting Bracket


  • Light Outlives Heating Element
  • Holds Air Bubbles
  • Short Lifetime)1-2 Years)

Marineland is one of the lowest costing, while still reliable, 10 gallon aquarium heaters out there. Just like their lights and hoods, Marineland heaters do not disappoint.

The heater can be set using 1 degree increments and is held within 2 degrees of the settings depending on how cool the house is and where it is placed.

A big note:
When the Marineland heater becomes exposed to air it will automatically shut off, as most heaters do. However the heater often needs to be unplugged for 30 minutes while fully submerged to reset the heater and turn it back on.

The mounting bracket is a handy tool, as it holds the heater in place far better than normal suction cups. Additionally you can remove the heater without removing the suction cups or moving the bracket.

When you first use the heater be sure to rotate it a full 360 degrees. This model is known to trap some air bubbles that can harm the heater and shorten its lifespan.

Lifetime & Warranty

As I’ve mentioned several times before this heater has a fantastic lifetime warranty. Combine that with Marineland’s excellent customer service, contacted at at 1-800-322-1266, and you get a warranty that cannot be beat.

The heater itself will live between 1-2 years. This is a bit short but when you get a replacement or two the lifetime can really last a lot longer. Just be sure to have a backup heater for these outages.

Eheim Jager 50 Watt

I love this company, and for good reason. The Eheim Jager makes the most reliable 10 gallon aquarium heater.

Cost: Medium
Warranty: 3 Years
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  • Durable Design
  • Efficient Heating Element
  • Precise Control
  • Long & Reliable Life
  • 3 Year Warranty
  • Multiple Safety Features


  • Older Look
  • Large Size

Consistency is what Eheim is all about, and the Jager really shows that value. The heater is still made by the original manufacturers in Germany with multiple safety features, high quality and revolutionary design that other brands just can’t figure out.

Jager model heaters hold an accurate temperature reading at all times and heat more efficiently than other brands of heaters. This and many other benefits owe thanks to Eheims special laboratory glass casing. It transfers heat easily yet cannot harm livestock. No more burning snails or high electric bills from this heater.

The Jager has no fissures, divots/abnormalities which helps ensure a long lifetime. Additionally the glass is unbelievably strong. Multiple times have I heard large live rocks fall onto this heater only to find it not only working, but unscratched. Even more impressive was finding parts of the rock broken off from the fall.

Adjusting the Eheim is fairly simple. Turn the blue ring located on the top of the heater to your desired temperature. Unlike other heaters the heat will actually go to the displayed number.

The Jager model shuts off automatically when exposed to too much air and resumes when resubmerged.

The only problem with the Eheim Jager is its size. The 50 watt model is 9.6″ x 1.4″. Only an inch or so larger than other heaters, but still something to take note of.

Lifetime & Warranty

Eheim offers a 3 year warranty on all of their heaters. This is pretty good but will almost always go unused.

On average the Eheim heater lasts between 7-20 years with the high end being more common. For this reason I will always consider the Eheim Jager to be the best 10 gallon aquarium heater of all time. If you don’t mind the older look and want to pay just a bit more for a quality heater, the Eheim Jager is the right choice.

Fluval E Electronic Heater 50 Watt

The Fluval E Series is a high end, multifunction heater that brings a lot more to the tank than any other heater.

Cost: High
Warranty: 5 Years
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  • Temperature Warnings
  • Digital Display
  • Extreme Precision
  • Built In Memory
  • Dual Temperature Sensors
  • Protective Casing


  • Higher Cost
  • Bulky Design

The Fluval heater measures 9.75″ x 2″ x 1.125″ and is set in .5 degree increments using the lever located on top of the heater. The heat is always displayed on the digital display, which has a few notable features:

  • When Blue the heat is too low/the heater is on
  • When green the heat is at the right settings
  • When Red the water is too hot, meaning something else is heating the water
  • When flashing the water is having the temperature changed too rapidly
  • When LF is displayed the heater is receiving very little water flow. More water flow allows for more even heat distribution

The Fluval E 10 gallon aquarium heater features a built in memory that resumes whenever the heater is powered. A much needed feature as their is no manual knob.

Additionally the heater features dual heat sensors, something no other heater has, to ensure perfect temperatures. These sensors are located inside the casing and are allowed to touch the water directly, Unlike other heaters that can only measure the internal air temperature of the heater.

The case itself is made of a durable plastic that prevents damage to any of the heaters important components. Additionally this prevents any livestock from touching or crawling on the heating elements, protecting them even more than Eheims special glass.

The triple suction cup mounting bracket is absolutely amazing at staying in place and allows the heater to be removed without touching the suction cups. The suction cups are actually strong and will not slide off like almost every other piece of equipment does.(Don’t even get me started on my power head)

Lifetime & Warranty

Fluval offers a solid 5 year warranty on their E-series and always help out their customers.

The heater itself will last around 3-4 years on average, which when combined with that long warranty gives you around 5-9 years of lifetime.

Looking for more heater suggestions? Check out the more general Best aquarium heater page.

Finding The Best Small Aquarium Heaters of 2018

Marina Betta Terta HT Hydor Slim Cobalt Mini Eheim Jager Aqueon Pro
Tank Size .5 – 1.5 Gal 2 – 10 Gal 1 – 10 Gal 1 – 2 Gal 3+ Gal 7+ Gal
dimensions 1.75″ x 2.75″ 5.5″ 6.5″ x 3.2″ 4″ 9″ 9″
Temp Display F/C F/C F F F/C C
Longevity 1 – 2 Years 1 – 3 Years 1 – 4 Years 2+ Years 3+ Years 7+ Years
Warranty 30 Day 2 Year 30 Day 3 Year 3 Year Lifetime
Price Medium Medium/High Medium Medium/Low Medium Low

Compact Quality in Heaters

While many larger tanks can take on whatever brand or heater is the most trusted or you are most familiar with, small aquariums just don’t have that freedom. Instead we need to pick from the best, most compact heaters that are reliable and effective. This means sometimes foregoing the use of automatic shut off heaters or temperature controls. To do this we need extensive knowledge about the heaters we will be using, ensuring that our fish will not be harmed.

#1 Marina Betta

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The Marina Betta is a common first choice thanks to its small profile, reliability and low cost. The heater is constantly running, meaning it works best in houses with a consistent temperature. The Marina Betta can keep tanks up to 1.5 gallons warm in most houses, less or more depending on the rooms temperature.

Most issues seen with this heater are when people keep the tank in a room that gets far too hot or cold occasionally. This heater is not designed to adjust to changes like that. Only use constant heaters in rooms that are kept a consistent temperature.

Unlike most aquarium heaters, the Marina Betta can also be buried underneath the substrate. This is thanks to its always on nature. What usually happens when you bury heaters is they heat the substrate around them before the heat is then transferred into the water, keeping the heater extra warm. While other heaters thermometers will incorrectly read that the tank is too hot and turn off, the Marina betta will keep going. This does mean, however, that you should keep your own eye on the tanks temperature when first putting the heater into place. Additionally check the tanks temperature when the houses heat changes. You may need to add a timer to this heater to have it working part of the day during hotter seasons.

#2 Tetra HT

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The tetra HT is my second choice for small aquarium heaters for a couple of reasons. First off it is one of the smallest aquarium heaters to come with an electronic thermostat, keeping your tank from getting too warm and harming the fish. The lack of temperature control is a great feature when your tank will be around children who want to touch the aquarium. It’s sleek design makes it easy to hide in the tank and the low cost makes this a low commitment heater.

That’s not to say the heater is low quality. The Tetra HT will almost always last over two years. Some people will go the safe route and replace it every year, but I find the excessive. Just keep a thermometer on the tank, check it every day or two and your tank will be fine.

There are some close competitors like the Hydor Theo Which works similarly and has a controllable temperature, however the cost is a bit higher and the heater is much harder to hide in the tank. If you can manage to hide the Theo you can certainly consider it, but I much prefer the simple look and no temperature adjustments of the Tetra HT for small aquariums that are fine at 78&deg.

The Two year warranty is a nice add on for this low cost aquarium heater. More often than not, as long as you are friendly and have your purchase info on hand, Tetra will be more than happy to help you out even past the warranty.

#3 Hydor Slim Aquarium Heater

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The Hydor slim heater functions much like the Marina Betta. It runs constantly and does not have a shut off mechanism. The flat design of the Hydor Slim does take up the least space of any small aquarium heater. Place a few small rocks or substrate on top of the heater and it will stay in place, even in tanks with powerheads running.

The cord Measures out to be just over six feet, letting you place the tank wherever you like. Hydor does back this small heater with a two year warranty. Just be sure to keep track of the proof of purchase, as you will need to send that in along with the heater to have it repaired or replaced. Remember you will need your own shipping box for this particular heater, so either keep the box on hand or use another similar sized one in its place. I personally keep a few boxes compacted in the closest incase any of my household appliances happen to break down. Always nice to have some boxes and they can be a bit costly depending where you live.

#5 EHEIM Jager Aquarium Thermostat Heater

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While I much prefer this heater in larger tanks, the Eheim Jager is simply so efficient, safe and reliable that I cannot ignore it. It is a bit long for most small tanks, however if you can fit the nine inch heater into your tank I highly advise you do so. Keep in mind the temperature display is Celsius only, but this only takes a minute or two to convert to Fahrenheit if you need to.

The simple design relies on their unique lab created glass that allows the Jager to transfer heat more efficiently than any other heater while still being nearly indestructible. Despite it being at a minimum of 50 watts, it still costs less to run the Ehiem Jager than any other heater. Couple this with the thermo safety control and you can make your small aquarium much cheaper to maintain while also removing any chance of cooking your fish. The only big draw back is the size.

#6 Aqueon Pro Heater

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A consistent supplier of excellent craftsmanship, Aqueon has set the standard with this low cost and highly reliable submersible aquarium heater. The heat reads in Fahrenheit and is perfectly consistent but runs 1 degree cooler than what it is set to.

The Aqueon features a life time warranty.Usually equipment will breakdown right when the warranty ends. Aqueon is one giant step above the rest of the competition here, allowing owners repairs and replacements whenever they need them.

A long warranty does not mean faulty equipment. The Aqueon Pro Heater actually has several new safety features you wouldn’t notice until something went wrong.

  • The heater automatically shuts off when removed from water, restarting when submerged in water. No risk of burning your hands when moving the heater around.
  • A no glass design keeps the heater from shattering from small drops and quick temperature changes.
  • 5 Sizes, one of which is 50 watts, allows us to fit this high quality aquarium heater in small tanks.
Room Temperature 50 Watts 100 Watts 150 Watts 200 Watts 250 Watts
Cold Room (68&deg F) 14 Gal 19.5 Gal 37 Gal 52.5 Gal 60 Gal
Normal Room (73&deg F) 17 Gal 25 Gal 46 Gal 64 Gal 75 Gal
Warm Room (78&deg F) 20 Gal 30 Gal 55 Gal 75 Gal 90 Gal

While we are focused on the 50 Watt, it’s nice to see how consistent the heater is in larger sizes. While you may have noticed the tank sizes it can cover are well above small tanks, this is not an issue. The heater shuts down automatically when the tank reaches the desired temperature. This means, unlike always on heaters such as the marina betta, the Aqueon pro will shut down when the room gets warm and the tank does not need heating. A really valuable trait for those of us with unpredictable weather.

Be sure not to bury the heater in gravel unless you really know what you’re doing. This will cause the heat to stay around the heater, keeping its thermometer from working properly. Usually this will result in the heater running far less than it should, keeping the tank cold.

For setting the heat a standard turning knob is located at the top of the heater, complete with number readings to show you where your water will be heated to. Underneath the rim lies the red/green indicator light that switches on, green, and off, red, signaling when the heater is in use.

As this heater is designed to be used in tanks with strong water flow, its suction cups will not fail. I find this to be a big pro. Any extra time I have to have my hand in the small tank is time spent adding oils and waste to the tanks small ecosystem.

Niche Bonus: Hydor’s Inline

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The Hydor Inline aquarium heater is the best possible option for small aquariums as it does not go inside the tank. However it requires some form of water movement outside of the tank. Inline aquarium heaters work by passing water through the heater, heating the water as it is moved through the system. The heater continues to run until the tank hits the right temperature and shuts off, becoming a fancy looking part of the tubing.

Creating a water system isn’t difficult. It could be something as complex as a sump, central water system for multiple tanks or even something simple like a Canister Filter. As long as there is tubing with water running through it to the tank regularly, the Hydor Inline aquarium heater will keep the tank warmed.

Here are a few of my favorite features for the Hydor:

  • It comes complete with a two year warranty
  • The average lifetime is over three years
  • It is incredibly efficient, both energy and heat distribution wise
  • Works for all tank sizes
  • Extremely durable with powerful connections to prevent leaks

The only major downside is that this heater only comes in 200+ watt sizes. This does, however, make it much cheaper to move to a larger tank if you choose to do so. I know I got my first 50 gallon only a few months after a 10 gallon.

The installation is quick and easy, just connect the tubing to both ends and tighten the red knobs on the top and bottom of the heater. These bite down onto the tubing, making a powerful connection that won’t weaken over time.

Best Inline Aquarium Heater

One part of the aquarium hobby will remain constant throughout the flow of time. Tanks need heaters. The problem? Heaters can look intrusive or down right ugly, lowering the appeal of our in home aquariums. To combat this companies have been scrambling to make new, effective ways to heat tanks safely without breaking the bank.

After a lot of niche products such as the tiny circular Betta heaters cam the emergence of the inline aquarium heater. Out of the tank, highly efficient and finally affordable, inline aquarium heaters have come in to finally butt out the long lasted rule of stick heaters.

How Do Inline Aquarium Heaters Work?

The concept behind these heaters is a fairly simple one. The water passes through a pipe/tube to reach either your canister filter, sump or refugium. After the water has finished there it passes on to the return pump. On the way back up water passes through the inline aquarium heater and has its temperature raised. This process continues until the water has reached the right temperature. After that the heater shuts off and acts as an adapter between the return line and canister filter/sump/refugium. Simple and effective.

So What Makes The Best Inline Aquarium Heater?

Ever since the evolution from stick heaters to inline aquarium heaters the world of aquatics has been drastically changed. The main things we look for in our inline heaters are:

  • Precise temperatures
  • Easy to use
  • Efficient heating elements
  • Long equipment life

Any heater filling all of those categories is more than suited for even the most spectacular aquariums the world has to offer.

Being able to maintain our water at the perfect temperature without having to introduce a distracting metal or glass stick heater is a big plus. Without the sight of equipment in the tank we create a much more realistic enclosed ecosystem. There’s no distractions, just aquatic life and their habitat.

Easy to use and long life both fulfill the same need. If the inline aquarium heater is nearly impossible to set up or cannot stay set up long then it is of little use to us. While it may seem as though a difficult set up shouldn’t be an issue you will be needing to remove the heater for some reason or another. Typically this is for maintenance on the return line of the heater or replacing the line to make it a different length. Either way if it was hard to set up the first time when we have instructions in hand the device becomes next to useless years later when we lose the instructions or forget what the item was called.

Reaching that point requires the long life of the best inline aquarium heater. As to be expected with much nicer and newer equipment, inline aquarium heaters often run more expensive than normal stick heaters. If they died every year or two there would be no way to justify the extra price point. No matter your budget wasted money is wasted money. Because of this we need a heater with at least two years of life time, with longer always being better.

Hydor Inline Aquarium Heater

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As the top inline aquarium heater, Hydor really hit all of our marks. This inline heater:

    • Protected by a solid two year warranty, guaranteeing a life of over two years, typically three at the least


    • Temperature settings that stick within 1 degree of the chosen setting


    • Highly energy efficient


    • Can often heat tanks up to 125 gallons in size


  • Is highly durable and has a strong grip on its connections

Coming in with either 200 or 300 watts, this inline heater is meant for bigger tanks. Granted it can be used for smaller tanks I don’t think it’s possible to justify the use on such small tanks. The 200 watt comes in both 1/2″ and 5/8″ connection sizes while the 300 is set to 5/8″ size. These tubing can usually be found at any hardware stores, but like most cases the best prices are found online


installing they Hydor inline aquarium heater is a straightforward but non flexible task. Begin by shutting off the water flow of whatever it is you are connecting the heater to. While this is not necessary I find it a lot easier to work with pipes that aren’t pouring out water.

I like to install the output portion of the inline aquarium heater first, as the return line will give it support while you do the rest of the work. It’s also a heck of a lot easier, as the tube that fits the heater is perfectly suited to being the return line. Simply slide the tube over the output end of the external aquarium heater and then turn the red knob to secure the tubing in place.

A neat trick I learned awhile back is that if your tubing is a bit too small to fit over the heaters connections you can remedy the issue by simply place the tubes end in hot water for a little under a minute. This expands the tubing, allowing you to set up the heater before it contracts, giving you one of the strongest connections possible.

With the return line set up you will need to put it into its final position where it will sit for years. This can be any set up you want, ranging from a tube hanging in the water all the way to a full drilled tank.

As for the other end you will need to connect your return line to the input portion of the heater. This is where a bit of research comes into play. For the easiest installation you will want to find out what size tubing you have been using. More often than not it will be a size that the heater is inherently compatible with. If however you need an adapter be sure to order this ahead of time. It’s no fun to get a new piece of equipment just to have it sit around.

Connect the tubing from your water pump into the bottom of the inline aquarium heater or adapter and then screw it into place with the red knob.

With all the connections complete you will need to set your heater in its final resting place. Keeping the heater vertical is essential. If you keep the heater on its side or upside down it will collect bubbles in the temperature control, preventing the heater from stopping at the right time. This is often a one way ticket to boiled fish.

Once the inline aquarium heater has been built into your return line you can switch back on the water flow. The heater itself does not need to be on yet as water can freely pass through anyways. In fact it is always best to allow your heater to adjust to the aquariums temperature before switching it on. Once the heater has settled in you can plug in the heater and set your desired temperature.

Maintaining The Temperature

To set the temperature there is a knob located near the bottom of the heater. Turning it to the left will lower the setting while turning to the right will raise it. The desired temperature setting should be left to rest next to the red light/arrow. The settings can range from 62-94 degrees Fahrenheit.

This is where my years of paranoid living may come in handy for you. Because aquariums can be so costly I always install my heaters with an aquarium heater controller. While most of the best aquarium heaters can be trusted, one malfunction is all it takes. Luckily when I was struck by one of these heaters gone haywire my controller put a stop to the boiling intent of the heater. Additionally this extended the life of my heater. How is that possible? When my heater became a “stuck on” the aquarium heater controller allowed me to continue using it anyways by shutting of the heaters power when the correct temperature was reached. Combining the heater controller with the Hydor creates a powerful heating duo that can support your tank for well over 5 years.

Avoiding Clogs

Our biggest fears when plumbing is involved are leaks and clogs. The heater itself cannot prevent leaks and will not create any leaks on its own. This leaves us only with the fear of clogs. Unlike clear tubing we cannot see what is inside the Hydor inline aquarium heater. For this reason it is strongly recommended you refrain from placing the heater on the intake tube of your system. Once the water passes through your filter, sump, or refugium it is far less likely to carry any debris. This allows for a safe return with almost no chance for clogs. Should anything manage to get through and into your heater you will quickly notice a decrease in water flow. The reduced chance of passing debris means the clog will only throttle the water speed and not fully shut it before you can fix the problem. I cannot stress it enough, use this heater on the return line only!


I was quite blunt with this earlier, yet I know how much we need verification on something like warranty. In addition to amazons own 30 day warranty on every object, Hydor themselves covers any replacement or repair costs for two whole years. Should the heater brake multiple times or you decide the heater is just not right for you after it does break they are more than happy to issue a refund rather than a return. They give amazing customer service with no fear of loop holes or replacement rejection.


Ok so we know that the heater can be replaced for two long years. Now what good is that if the heater is constantly breaking down and being sent in? To be considered the best inline aquarium heater Hydors quality comes into question. For this piece of equipment the reviews have always been top notch. It would be absurd to base this only upon my never broken inline heater. Thankfully those who have used the Hydor have spoken out and shown that the average life time of this heater can last well over 3 years, some even reaching into the 12 year mark. More than impressive as heaters are constantly switching on and off.

For those wondering if the salt in marine tanks could wear down the heater Hydor has pulled through again.

Keeping salt degradation in mind the heater comes built with a glass tube for the water to pass over. This prevents any of the wear that metal or plastic items receive via constant salt interaction.

Heating Strength

While I cannot simply tell you to disregard the rules of normal heating requirements, I must say this heater seems to be far more effective at its job than normal tube heaters. In many cases a single 300 watt inline aquarium heater is able to keep a 100+ gallon tank heated up. This occasionally happens with some of the best aquarium heaters but is not common place. This means the Hydor inline aquarium heater is easily most cost effective than normal tube heaters and can even cost less than normal heaters. With most heaters you will end up needed multiple sticks to heat large bodies of water. The inline heater however will get the job done with just the one in most cases. If you keep your house especially cold however then you may still need a second heating element. This has never been the case in my time with the Hydor however.


The Hydor Inline Aquarium Heater offers an amazing amount of value for something as simple as a heater. The life time is often over three years with a two year warranty. It can heat tanks of a much larger size than normal stick heaters while staying at a low power cost. Combined with the fact this inline aquarium heater can replace two stick heaters it often saves money in the long run. Installations is simple but must be done with care. Plumbing is no joke and leaks can cause serious damage if done carelessly. Once installed correctly the design of a glass interior and shock resistant exterior prevents all damage. Unless you attack this heater it isn’t going anywhere. As my final note I want to remind everyone to always position inline aquarium heaters upright. Sideways and upside down can trap air bubbles and fry your fish due to incorrect temperature readings. If you’ve managed to read this far it’s likely that the inline aquarium heater suits your needs. Don’t hesitate to check one out as their lifetime and efficiency will easily surpass a traditional stick heater when used correctly.

SunSun Bargain Heaters

Given the long life that our fish and corals have, it’s no doubt that owners will find themselves with a broken heater at least once in their life. Ordering replacements of your exact heater is always a good idea, while getting the heater repaired for a discount or free is even better. No matter your choice there remains one problem. What do you do while you wait for your old heater or new heater to come in? In this one instance I recommend you use a bargain SunSun aquarium heater.

Are these heaters optimal? Not really. They do however come with some strong heating elements well below the average cost of a higher quality heater. Keeping a replacement near by could easily save you from lost fish or stunted coral growth while remaining the cheapest component you order.

The SunSun 500 Watt Heater

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Simply put, unless you get a deal from someone you know, no heater can match the SunSun price for such a high wattage.

The 500 watt heater measures at 14 inches long and can heat any aquarium that it fits in, up to 125 gallons in size. As the heat has no special gimmicks the heater can be angled however you like. Just keep the rod submerged and you will have no problems.

Quick Note: The SunSun 200 watt heater has the same design and roughly half the price. If you want a smaller back up keep the 200 in mind.

The heat output is reliable and the heater is covered with a one month warranty. Given one of the main problems with SunSun aquarium heaters is the number that show up and don’t work, the warranty ensures you get a heater you can store for use later. Just be sure to check it actually heats before storage.

Unlike many newer heaters, the SunSun does not have shatter proof glass and only holds a shatter proof design. Essentially this means it has the rubber guards on both ends. This makes the heater able to take most in tank abuse with the big danger being removal of a hot or turned on heater. Remember to always unplug and allow this heater to cool down before removing from water.

One of the more questionable features of the SunSun is the temperature range. Every fish you keep will be covered under this heater no doubt, but take extra care when turning the heat up. The dial atop the tube can be set all the way up to 93 degrees Fahrenheit. Needless to say carelessly turning the heat up too high to make the water heat faster can leave your fish cooked if the heat is not dialed back in time.

Like most aquarium heaters the SunSun does indeed come with an overload switch. This prevents the heater from surpassing the set temperature. This sensor only senses ambient temperature however, meaning if the heater is left in open air it will stay on until it breaks. The SunSun must always be fully submerged

The Big Downside

Before you run out and buy the SunSun remember I only recommend it as a back-up heater. When used for many months in a row the SunSun is proven to have a shorter life span than most heaters. I personally suggest you use the best aquarium heater you can find for full time use. However if you have many valuable fish and coral like I keep, you will want to hold onto a back-up heater as a safety measure. Rather than running to Petco or Walmart for a couple 100 watts, keep a SunSun at home for the inevitable heater breakdown.

Aquarium Lights Heating Up Water

When setting up new fish tanks there’s a lot to keep in mind. Finding the right heater and controller to keep the perfect temperature is a step in the right direction but there is a bit more to heating than that. Namely overheating.

When summertime comes our heaters often get long breaks. The problem is our aquarium lights are never given that opportunity. While powered many lights can emit heat, some far more than others. For instance an LED light will often be warm to the touch as it gives off heat. If, however, you touch a florescent light you will quickly discover it’s as hot as a stove top! hanging these lights above tanks will cause the water temperature to rise, which is usually fine. During warm weather is when the aquarium lights heating up water becomes a problem.

How Much Heat Do These Lights Give Off?

In order the typical heat out put goes metal halide, mercury vapor, incandescent, power compact, full spectrum florescent and finally LED lighting. Metal halide is so hot that it is actually dangerous to handle as they will stay hot long after the power is removed.

With the lighting types all sorted there’s a few more factors that determine the heat your lights will be transferring to your tank. The first note is placement. Many large reef tanks will have these lights suspended over the tank with no lid. This allows the air to flow freely and cool off with the surface exchange. With that problem out of the way the lights can be closer to the water and allow for the most light to reach corals. An optimal set-up in most situations.

A more common set-up in the household is the aquarium hood with a light installed inside. This keeps all the heat in the casing, meaning more of the heat will transfer to the air between the light and the water, thus heating the water. A small amount will transfer into the hood and then the outside of the tank, but this will be minimal. These set-up are the ones that can really cook our fish in the summer time.

The set-up I prefer to use is a light strip placed above the tank with a glass lid between the two. This keeps almost all of the heat out of the tank while still allowing the light to be close. The use of glass between the light and tank does reduce the light that corals get but only by a small amount. More importantly it protects the light from mist and keeps the tank cool during hot summers. This allows me to run tanks year round without the use of chillers.

How Can I Reduce The Heat From Aquarium Lighting?

As previously stated my favorite method of reducing light heat creeping into the tank is the use of glass lids between the tank and the light. This combined with normal home temperatures or around 75 degrees is enough to keep my tanks cool. If more cooling measures must be taken here are a few tips:

  • Turn up the AC: While this may seem like a silly answer many homes with heated pets(fish, lizards and even birds) can find themselves with a higher temperature than the thermostat is reading. I first discovered this when my house turned into a frozen tundra. Turns out my tank was directly by the thermostats sensor so the AC was constantly on. If your tank is far away from the AC it may not even notice the heat.
  • Increase Aeration: This may seem a bit odd but by increasing the amount of aeration will actually reduce the heat. This can be done with filtration or circulation. Pointer power heads to make the water move more will keep the surface cooler and allow the water and oxygen to trade heat. This method does not work for hooded units.
  • Close the curtains: Silly right? Not at all. Often the solution to our problems is rather simple, we just don’t see it. When the tank is constantly hit by strong rays from the sun it will always rise several degrees. Not only that but even more algae will grow from the suns rays! Tanks are often meant to be placed away from the windows but just incase yours ended up in direct light, shut those curtains.
  • Use tank chillers: This is a bit more costly but if your tank is always too hot and your home is kept fairly cool there are few other choices. A chiller will always maintain the temperature just as a heater will, turning on only when the tank gets too hot. Once a chiller is installed owners never have to worry about overheating in the tank again!

There may be times when you need to quickly cool off your tank rather than apply a long term solution. This could be because a heater got stuck on or you left the AC off when you left the house. Either way here’s a few quick ways to get the temperature down safely:

  • Use frozen water bottles: This is a handy trick that can reduce the heat quickly and safely. Simply take a bottle and fill it with ice, cold water or preferably freeze it if you have time. Place these in the tank and ensure they have a tight lid to avoid adding untreated water to your tank. The cold bottle and contents will absorb the heat of the tank and lower the temperature without causing any additional evaporation.
  • Aim a fan at the surface of the water: Unlike the previous method fans will increase the amount of evaporation in the tank. If only used for a short time however this can be considered a non-factor. The fan blows cooler air into the water and stirs the water so that the same water is not always near the surface. Combine this with the bottle tip and the tank will cool rapidly. Just don’t cool it too much too fast.

Finding The Best Aquarium Heater 2018

Aqueon Pro Heater Fluval E Series Finnex Controlable Hydor Theo Eheim Jager Via Aqua
Wattage 50-250 50-300 100-500 25-400 25-300 50-300
Tank Size 10-90 Gal 10-100 Gal 10-120 Gal 2-105 Gal 4-260 Gal 8-80 Gal
Temp Display F/C F/C F F C F/C
Longevity 3+ Years
Lifetime Warranty
4+ Years
5 Year Warranty
5+ Years
6 Month Warranty
3+ Years
2 Year Warranty
7+ Years
3 Year Warranty
2+ Years
30 Day Warranty
Price Medium Medium/High Medium Medium/Low Medium Low

What Makes The Best Aquarium Heater?

With such weight attached to the right heat we need to ensure our heaters can really be more than just a hot stick in the water. Adjustable heats, auto shut off features, shatter resistant materials and precise temperatures are what I have sought out to find best aquarium heater on the market. A few other factors to keep an eye on are the life time of the heaters, resilience along with their warranties. For this guide I have selected the best aquarium heater choices for large aquariums, medium household aquariums and small fish tanks.

#1 Aqueon Pro Heater

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A consistent supplier of excellent craftsmanship, Aqueon has set the standard with this low cost and highly reliable submersible aquarium heater. The heat reads in Fahrenheit and is perfectly consistent but runs 1 degree cooler than what it is set to.

The Aqueon features a life time warranty.Usually equipment will breakdown right when the warranty ends. Aqueon is one giant step above the rest of the competition here, allowing owners repairs and replacements whenever they need them.

A long warranty does not mean faulty equipment. The Aqueon Pro Heater actually has several new safety features you wouldn’t notice until something went wrong.

  • The heater automatically shuts off when removed from water, restarting when submerged in water. No risk of burning your hands when moving the heater around.
  • A no glass design keeps the heater from shattering from small drops and quick temperature changes.
  • 5 Sizes ensure your tank is never fried by an oversized heater. Sizes range from 50 watts to 250 watts.
Room Temperature 50 Watts 100 Watts 150 Watts 200 Watts 250 Watts
Cold Room (68&deg F) 14 Gal 19.5 Gal 37 Gal 52.5 Gal 60 Gal
Normal Room (73&deg F) 17 Gal 25 Gal 46 Gal 64 Gal 75 Gal
Warm Room (78&deg F) 20 Gal 30 Gal 55 Gal 75 Gal 90 Gal

If you’re reading the review on amazon you may have noticed their claim of “nearly indestructible.” This is 100% true and helps enforce the claim that Aqueon is the best aquarium heater brand available. No reasonable drop puts a dent in the heater. Even rough bumping with rocks or resting 40 gallon buckets on the heater could cause it any damage. To break this heater you will really have to have some malicious intent behind your handling

For setting the heat a standard turning knob is located at the top of the heater, complete with number readings to show you where your water will be heated to. Underneath the rim lies the red indicator light that switches on and off signaling when the heater is in use.

To attach the heater to your tank a set of suction cups comes with the heater. These will hold under even my powerful 1k gph power head’s water flow and allow you to angle the heater however you like. Sometimes a diagonal is needed to fit behind those odd shaped rocks.

#2 Fluval E Electronic Heater

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One of the more high tech looking heaters, the Fluval E Electronic Heater is a strong component ready to make its tank successful. The wattages available range from 50 watts to 300 watts, letting the Fluval fit into any aquarium. Really this is the best aquarium heater with a more modern look.

Room Temperature 50 Watts 100 Watts 200 Watts 300 Watts
Cold Room (68&deg F) 10 Gal 20 Gal 43.5 Gal 66.5 Gal
Normal Room (73&deg F) 12.5 Gal 25 Gal 55.5 Gal 83 Gal
Warm Room (78&deg F) 15 Gal 30 Gal 65 Gal 100 Gal

The biggest draw to the Fluval is its LCD display. Not only does it constantly update in an easy to read numerical display, the display even gives indications of any problems the tank could be experiencing. While the water is the right temperature the light stays green. When the screen changes color the temperature is not what it is set to. If the screen turns red the water is too hot and the heater is not on and if the screen turns blue the water is cold which turns the heater on. You should only really notice this when first installing the heater or during extreme weather. Remember heaters don’t lower heat. In cases of extreme temperature swings the screen will begin flashing, immediately alerting the owner to any problems.

Should the Fluval lose power the temperature settings will be saved and resume upon receiving power. No cold/melted fish after a midnight blackout.

With all these temperature safety features you may think the temperature is holds is inconsistent. The Fluval actually effectively combats this fear by equipping itself with two temperature sensors. This gives the Fluval an even more precise reading than all single stick heaters that can only rely on one reading and keeps your tank safe in the event of hardware failure.

To safeguard against any kind of failure or damage, all Fluval heaters come standard with a long five year warranty. Any breaks, failures or faulty parts will be replaced or refunded by Hagen, Fluval’s company, themselves. Be sure to keep track of your proof of purchase, which can be anything from a receipt to the order conformation email.

To allow for the most precise temperature changes available the Fluval comes with a lever rather than a knob. This lever changes the degrees in .5 degree increments, removing the “close enough” feeling that knobs and dials can create. To make the temperature even more precise the Fluval uses an internal thermal sensor, which is as accurate as an external water probe. Most heaters simply sense the internal air temperature which can cause the heat to fluctuate throughout the day. Adding on even further is the heaters low flow sensor. If the Fluval determines that the heater is not receiving enough water flow the screen will display LF on the screen. simply put the Fluval lets you know when it is not in an optimal position. Because of all these features the Fluval earns the title of best aquarium heater at maintaining perfect temperatures.

A small, but surprisingly nice addition is made by the casing of the heater. Rather than an exposed rod, this electronic heater comes with a built on guard to prevent contact with aquarium inhabitants. While this may seem pointless, tanks with snails may understand this importance. Snails will often climb onto the heater due to its minor warmth and begin cleaning the heater. However once the heaters flip on the snail starts to cook and lets go, often falling on their back and dying unless saved by the owner. I personally have lost many a snail this way and am happy to keep them all alive now thanks to this protective guard.

For those still reading the final detail I have is the back mounting system. The Fluval has a triple suction cup mounting bracket that attaches to the back of the heater. For servicing and cleaning the heater can be detattched from the mounting bracket so that you do not have to reposition the heater once it is ready to be mounted again. The suction cups are fairly strong and are more resistant to warping than cheaper suction cups. Never the less keep the area under the suction cups clean to create the best holding strength possible.

Overall the Fluval E Electronic Heater brings a lot to the table that no other heater does. The modern design and dual sensors for added safety are just icing on the cake.

#3 Finnex Heater With Electronic Controller

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This heater is made with a durable titanium tube, making this one of the more durable aquarium heaters. Adding on the extremely convenient controller is just icing on the cake.

Unlike shatter proof glass heaters, the Finnex’s titanium tube can hold up to even large turtles ramming into the tube. Owners need not worry about over zealous fish with this indestructible design. A concern I had that was put to rest was the safety of my tank itself. Given such a hard tube the heater sounds dangerous to glass tanks. However both ends are covered with a shock absorbing plastic end that prevents any collision damage and scratches.

Boasting the widest range of all other heaters, the Finnex comes in 6 sizes ranging from the standard 50 watts all the way to a massive 500 watt size. That’s a huge range that covers 10 gallons all the way up to 120 gallon tanks.

Room Temperature 50 Watts 100 Watts 150 Watts 200 Watts 300 Watts 500 Watts
Cold Room (68&deg F) 10 Gal 20 Gal 30 Gal 60 Gal 80 Gal 100 Gal
Normal Room (73&deg F) 15 Gal 25 Gal 45 Gal 70 Gal 90 Gal 110 Gal
Warm Room (78&deg F) 20 Gal 30 Gal 60 Gal 80 Gal 100 Gal 120 Gal

The controller on this heater allows you to easily adjust the heat without having to reach into your tank or dabble with your sump. The controller has large, 2 degree increments shown with a small dial that points to where the heat actually is. Not the most precise setting but its still easy to get the temperature within a .5 degree range. The red light indicates when the heater is on while the green light shows that your temperature has reached the desired setting.

The warranty is a bit shorter on this one, however Finnex is well known for their quality aquarium products. If there are any faults with your heater initially send it back immediately! When these heaters work they work amazingly but nothing can save faulty parts or shipping damages. If the product does happen to fail within the 6 month warranty, Finnex will either service or repair your heater. If the heater outlasts the 6 month warranty it is unlikely to be one of the defective heaters and will live to see an average lifetime of four to five years.

Combining ironclad durability, longevity and a handy controller all at a decent price easily makes the Finnex a contender for the best aquarium heater.

#4 Hydor Submersible Glass Aquarium Heater

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A perfect balance between price and functionality, the Hydor Heater Theo model earns its spot here as the fourth best aquarium heater.

Going back to the glass tubing style, the Hydor comes with a large, easy to read red dial top. The arrow points to the temperature setting. Simple, easy to use and more precise than knobs. Underneath the temperature setting dial is a large, multi layered rubber cover. While it is rare to be shocked by heaters, it can happen. These extra layers make the Hydor much safer in that sense.

Because the all black and silver color of this heater I have been able to use it in many tanks who don’t want the heater to be a distraction while not adding on additional bodies of water such as a sump. Remember that you can set the heat before you put the heater in the tank, meaning you don’t need to touch the dial after submerging and hiding the heater.

A small, but incredibly nice thing I noticed with the Hydor is the strength of the suction cups. While heaters, power head and submersible filters all can end up falling off the glass, the Hydor has exceptional suction strength.

The Hydor also comes in 7 different sizes, featuring the smallest size on this list. 25 watts to 400 accommodate all tanks within the range of 2 to 105 gallon tanks.

Room Temperature 25 Watts 50 Watts 100 Watts 150 Watts 200 Watts 300 Watts 400 Watts
Cold Room (68&deg F) 2 Gal 5 Gal 14 Gal 23 Gal 26 Gal 53 Gal 80 Gal
Normal Room (73&deg F) 4.5 Gal 9.5 Gal 20 Gal 30.5 Gal 39.5 Gal 66.5 Gal 92.5 Gal
Warm Room (78&deg F) 7 Gal 14 Gal 26 Gal 40 Gal 53 Gal 80 Gal 105 Gal

There is an exception to this heaters power however. Many have noted that the heater is not suited for large temperature changes, making cold houses look elsewhere. For many of us who keep our homes at or above 70 the heater will have no problems, but getting over the 14 degree change line can require multiple heaters. This is well documented in the user manual, which of course cannot be read until the product is in your hand. For those who leave the heat off and allow their homes to reach 65 degrees other heaters may be required.

The warranty spans across two years, easily enough time to see if you have a bad heater. Those that out last this warranty will often see a life time between 3-5 years.

For those looking to buy be sure to measure your tank and think outside the box a bit. If you have an external body of water and need anything smaller than the 50, we suggest getting the 50 watt anyway. It has the lowest price even though it is not the smallest heater. Not only will this save you a bit of cash but the added wattage will be a safeguard against extreme cold where a higher wattage is needed.

#5 EHEIM Jager Aquarium Thermostat Heater

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This heater has something most heaters lack today. An older, more powerful look made from its original manufacturers in Germany. It works perfectly and had some newer features such as shatter resistant, special laboratory glass with a heat shield and crevice free design. This means livestock will not be harmed when touching the heater and large fluctuations in temperature will not harm the heater. Additionally the Jager aquarium heater features the automatic shut off when dry function. This clearly is Eheim’s candidate for the best aquarium heater for both large tanks and small tanks.

Despite the aged look of the Jager this heater comes with automatic temperature regulation that shuts off the heater once the desired temperature has been reached. Additionally the thermo safety feature is standard and prevents damage when the heater runs dry.

The Jager comes in sizes of 25 to 300 watts, allowing for tanks between 2 and 260 gallons to pick up a single Eheim Jager aquarium heater and be fully heated (no joke, check out their manual under downloads if you don’t believe me). Homes with low temperatures will need extra heating. 78 degrees is my dream house anyways. A lot of people disagree with me there however. If you have large temperature changes in a big tank you will need a second heater. Position the second on the opposite side of the tank and provide both with good flow for the best results.

Room Temperature 25 Watts 50 Watts 75 Watts 100 Watts 125 Watts 150 Watts 200 Watts 250 Watts 300 Watts
Cold Room (68&deg F) 4 Gal 6.6 Gal 15.8 Gal 26.4 Gal 39.6 Gal 53 Gal 79 Gal 106 Gal 159 Gal
Normal Room (73&deg F) 5.5 Gal 11 Gal 21 Gal 32.5 Gal 46.5 Gal 66 Gal 92.5 Gal 128.5 Gal 210 Gal
Warm Room (78&deg F) 6.5 Gal 15.8 Gal 26.4 Gal 39.6 Gal 53 Gal 79 Gal 106 Gal 159 Gal 260 Gal

With the old look comes the old standards. Seriously the Jager aquarium heater is built to last, surviving over five years in one of my reef tanks. During this time the heater has had multiple rocks fall upon it (looking at you pistol shrimp) without receiving a single scratch. Honestly the cord would probably be yanked from the socket before the heater breaks. Should the heater actually manage to be broken you may contact EHEIM as they give a three year warranty on their products.

If durability is your primary concern this is the heater for you. It is the most reliable aquarium heaters on the market. For peace of mind I highly reccomend the Ehiem Jager aquarium heater.

#6 ViaAqua Quartz Glass Submersible Heater

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This heater is a plain and simple, fully submersible heater with a hardened glass casing. Affixed to the front of the heater is its built in thermostat that quickly adjusts the heater to match your desired settings. This is set by turning the knob at the top of the heater, which slides the red bar sideways until it reaches the end and continues on the next level. whether the device is on or off is indicated by a small light at the top of the thermometer.

The sizing of these heaters ranges from 50-300 watts again, allowing you to use these heaters for any sized aquarium equal to or greater than a 5 gallon all the way up to 80 gallon tanks. Basically if the heater fits in the tank it can function safely.

Room Temperature 50 Watts 100 Watts 200 Watts 300 Watts
Cold Room (68&deg F) 8.5 Gal 16.5 Gal 33 Gal 53 Gal
Normal Room (73&deg F) 11 Gal 21 Gal 41.5 Gal 66.5 Gal
Warm Room (78&deg F) 13 Gal 25 Gal 50 Gal 80 Gal

The ViaAqua comes with 2 suction cups, allowing for free style placement that holds under strong water flow. While the box warns about being placed horizontally it has actually only received that warning due to a few owners turning the heater and causing the wire to become taut. This removed their drip loop and shorted their socket as any water would normally do. Just be sure you keep your drip loops in place.

Our two bad notes on this heater are it cannot fight cold rooms as well as others. When subjected to open windows during winter times the tanks temperature would drop a few degrees. Not too surprising but it dropped more than the above mentioned heaters. Secondly this heater is only recommended to be used in either pairs or with a controller. The failure rate on this heater is not high but is still present. combining two of these very low cost heaters will ensure tank safety as:

  • If one heater breaks and stays on permanently it will not have enough power to cook your fish. The other heater will shut off normally, maintaining a safe temperature while giving the owner time to discover the other broken heater.
  • Conversely if one heater breaks and no longer provides heat the tank will be kept warm by the other heater. Again this gives the owner a much larger window of time to fix the problem and keeps your fish, corals, and invertebrates alive.

Over all this is one of the best aquarium heaters for 10 gallon tanks as it has far surpassed its expected value vs price ratio. Even Generic brands at local stores cost more for lower wattages. While I usually stick to big tanks this is likely the best aquarium heater for small tanks. Truly a lot of value has been packed into this little heater. Just take normal safety precautions as with any heater.

Wrapping up our best aquarium heater guide

I know this has been a lot of information for something that can be seen as a simple matter. While it is true you can throw any heater in your tank and it will probably work our fish and corals can be expensive and deserve the best aquarium heater we can find. If not for your tanks at least for your peace of mind.

Looking for information on sizing your aquarium heater to your tank? read on at http://freshaquarium for an easy to read aquarium heater size guide.

Also be sure to check out my page on quiet aquarium powerheads.


Aquarium Heater Size Guide

When it comes to selecting the best aquarium heater size there is no “per gallon” rule that works in all cases. More often than not the size of your heater will be determined by the wattage and quality of your heater. This means the cheapest, biggest heater may not be the best aquarium heater. In fact it is often better to go for one of the better small, high quality aquarium heaters, such as the Eheim Jager.

Actions speak louder than words however. Therefore I have gone and created a list of tables to help you find the right aquarium heater size for your tank. This information has all be gathered from manufacturers, manuals, reviews and personal experience. This will help you make a much better choice than a “x watt per gallon” suggestion.

Additionally we must take into account our homes average temperature. A wind breaker doesn’t work too well during a snowstorm, so we can’t expect a heater to work just as effectively with huge differences in temperatures. For this I have done three ratings for homes at 68, 73, and 78 degrees Fahrenheit.

Aqueon Pro Heater
Room Temperature 50 Watts 100 Watts 150 Watts 200 Watts 250 Watts
Cold Room (68 F) 14 Gal 19.5 Gal 37 Gal 52.5 Gal 60 Gal
Normal Room (73 F) 17 Gal 25 Gal 46 Gal 64 Gal 75 Gal
Warm Room (78 F) 20 Gal 30 Gal 55 Gal 75 Gal 90 Gal
Fluval E Series
Room Temperature 50 Watts 100 Watts 200 Watts 300 Watts
Cold Room (68 F) 10 Gal 20 Gal 43.5 Gal 66.5 Gal
Normal Room (73 F) 12.5 Gal 25 Gal 55.5 Gal 83 Gal
Warm Room (78 F) 15 Gal 30 Gal 65 Gal 100 Gal
Finnex Titanium Tube
Room Temperature 50 Watts 100 Watts 150 Watts 200 Watts 300 Watts 500 Watts
Cold Room (68 F) 10 Gal 20 Gal 30 Gal 60 Gal 80 Gal 100 Gal
Normal Room (73 F) 15 Gal 25 Gal 45 Gal 70 Gal 90 Gal 110 Gal
Warm Room (78 F) 20 Gal 30 Gal 60 Gal 80 Gal 100 Gal 120 Gal
Hydor Theo
Room Temperature 25 Watts 50 Watts 100 Watts 150 Watts 200 Watts 300 Watts 400 Watts
Cold Room (68 F) 2 Gal 5 Gal 14 Gal 23 Gal 26 Gal 53 Gal 80 Gal
Normal Room (73 F) 4.5 Gal 9.5 Gal 20 Gal 30.5 Gal 39.5 Gal 66.5 Gal 92.5 Gal
Warm Room (78 F) 7 Gal 14 Gal 26 Gal 40 Gal 53 Gal 80 Gal 105 Gal
Eheim Jager

The Eheim earns a special note here. It has far above average heating strength thanks to its special laboratory glass, which you can read more about on the best aquarium heater page.

Room Temperature 25 Watts 50 Watts 75 Watts 100 Watts 125 Watts 150 Watts 200 Watts 250 Watts 300 Watts
Cold Room (68 F) 4 Gal 6.6 Gal 15.8 Gal 26.4 Gal 39.6 Gal 53 Gal 79 Gal 106 Gal 159 Gal
Normal Room (73 F) 5.5 Gal 11 Gal 21 Gal 32.5 Gal 46.5 Gal 66 Gal 92.5 Gal 128.5 Gal 210 Gal
Warm Room (78 F) 6.5 Gal 15.8 Gal 26.4 Gal 39.6 Gal 53 Gal 79 Gal 106 Gal 159 Gal 260 Gal
ViaAqua Quartz
Room Temperature 50 Watts 100 Watts 200 Watts 300 Watts
Cold Room (68 F) 8.5 Gal 16.5 Gal 33 Gal 53 Gal
Normal Room (73 F) 11 Gal 21 Gal 41.5 Gal 66.5 Gal
Warm Room (78 F) 13 Gal 25 Gal 50 Gal 80 Gal
Marineland Precision Heater
Room Temperature 50 Watts 75 Watts 100 Watts 150 Watts 200 Watts 250 Watts 300 Watts 400 Watts
Cold Room (68 F) 8 gal 13.5 gal 19.5 gal 26.5 gal 36.5 gal 46.5 gal 53 gal 83 gal
Normal Room (73 F) 10 gal 17 gal 25 gal 34 gal 45 gal 58 gal 66.5 gal 104 gal
Warm Room (78 F) 12 gal 20 gal 29 gal 40 gal 55 gal 70 gal 80 gal 125 gal
Aquatop GH
Room Temperature 50 Watts 75 Watts 100 Watts 150 Watts 200 Watts 250 Watts 300 Watts
Cold Room (68 F) 8.5 gal 13.5 gal 16.5 gal 26.5 gal 33 gal 43.5 gal 52.5 gal
Normal Room (73 F) 11 gal 17 gal 21 gal 34 gal 41.5 gal 55.5 gal 64 gal
Warm Room (78 F) 13 gal 20 gal 25 gal 40 gal 50 gal 65 gal 75 gal
Tetra HT
Room Temperature 50 Watts 100 Watts 150 Watts 200 Watts
Cold Room (68 F) 4 Gal 18 Gal 24.5 Gal 33 Gal
Normal Room (73 F) 7 Gal 24 Gal 37 Gal 44 Gal
Warm Room (78 F) 10 Gal 30 Gal 40 Gal 55 Gal
Room Temperature 50 Watts 300 Watts
Cold Room (68 F) 10.5 Gal 66 Gal
Normal Room (73 F) 13 Gal 72.5 Gal
Warm Room (78 F) 16 Gal 99 Gal
Aquarium Heater Size Graphs

For those who hate tables but don’t mind looking over graphs I have converted the data just for you. A quick glance is all it takes to find the perfect aquarium heater size for your fish tank.

Keep these tips in mind when deciding what aquarium heater size you need:

  • Small aquariums can be heated much quicker and should avoid oversized heaters.
  • Large aquarium heaters may not work as well as two smaller heaters. This is highly dependent on water circulation. Either choose two smaller heaters or direct strong currents towards your heater for the best results.
  • Always keep a back up heater! Even if your back up is a cheaper model it can still save your fish while you get a longer lasting model.

I cannot stress enough that the wattage of your aquarium heater is not the only factor for sizes. Cheaper models such as the Tetra HT cannot heat anywhere near Eheim or the Fluval E series heater. Only go for cheap heaters as back ups.

Aquarium Heater Controllers

If you’ve landed on this page chances are you have heard an aquarium horror story. Most often this is a result of a high quality aquarium heater suddenly breaking after years of service. The heater either never shuts off an proceeds to boil the fish alive or stops heating and freezes everything to death. Either way, owners then walk in the next morning to a tank where nothing remains.

So how can we prevent these atrocities? There are a few methods, each of which with their own draw backs. For those who seek the cheapest solution, getting two lower wattage heaters for one tank can be enough peace of mind. The idea here is that both heaters must break for the aquarium to be boiled or frozen.

While I do recommend this for expensive aquariums stocked with corals and high value fish, dual heating units is not enough to prevent accident. Unless the owner is checking their heat daily it is still possible for fish to be boiled or frozen before anyone notices.

So what is the fail safe solution? As you may have guessed from the headline aquarium heater controllers prevent both high and low temperatures. Some even go so far as alerting owners to any threats the heaters or other components may have caused. Should the aquarium continue to climb past the expected temperature the aquarium heater controller will shut off the heaters power until the tank needs it again.

While heaters do typically come with this function they are not reliable enough for tanks that can easily cost thousands of dollars. Simply put aquarium heater controllers hold a precise temperature regardless of heater health. In fact owners can even use “stuck on” heaters safely with a controller in place. This essentially gives you back every heater that’s ever broken this way. If you know other aquarists Be sure to take their stuck on heaters off their hands to save a nice chunk of money.

Aquarium Heater Controller For Tanks Under 100 Gallons

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To put the title more precisely the Finnex Max-300 Digital Aquarium Heater Controller is suitable for all aquarium heating setups 300 watts and under. For tanks needing much higher temperature changes and therefor wattages, see the next controller.

The 300 features the overheating protection we all so desire combined with a built in memory system. This allows you to set your temperature to exactly what you wish. I use mine to give corals the perfect temperature.

To install this controller you simply place the temperature sensor probe into your tank and keep the controller close enough so that the probe does not get moved when you use the controller. Next you plug your heater into the controllers power receptacle. It really is as simple as pushing the suction cup against the inner glass of the aquarium and swapping sockets.

Make sure to keep the sensor probe away from external heat sources. Allowing the probe to sense heat generated by a nearby radiator or light may cause incorrect readings.

The 300 has three simple buttons. Two buttons raise and lower the temperature while the third button turns the device on and off. While this may sound pointless it actually allows owners to shut off their heaters during water changes without having to fiddle with the wire mess aquariums always create.

Underneath the two temperature buttons are the indicator lights. The green power light shows that the controller itself is receiving power. This light should always be on when you run the controller. To the right of this green light is the red heater indicator light. This one shows when the heater is activated and is heating the aquarium. If you notice this light never shuts off, ensure your heater is able to reach the desire temperature. Remember large temperature changes can demand increased wattage

The socket is triple prong to allow any and all plugs to fit into the controller. I like to take advantage of this and use a splitter. By doing so I can use two separate heaters and create a more even and reliable heat source for my aquariums.

On the frame of the controller is a screw that allows you to attach the controller to any surface you would like. This may be nice for those with a permanent set-up but I personally find my controller in a new place each month. For this I use the included hanger to hook the controller into place.

Special Note:
I have been asked several times if the controller works with inline heaters. The controller does indeed work with any kind of heater, including inline, as the sensor is a probe placed in the water. Once the heat exceeds the temperature desired the heater is shut off.

Finally the warranty on the controller lasts up to 6 months. If your controller makes it this far without breaking then it is safe to assume you got the standard high quality the controller is known for and not a faulty unit.

For under $30 the controller can save aquariums from the disaster of boiled/frozen tanks. The controller is easy to install and supports all heaters up to 300 watts.

Aquarium Heater Controller For Tanks Over 100 Gallons

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For any and all tanks that manage to reach over 100 gallons (This does include additional bodies of water such as sumps, canister filters and pipes) I fully recommend the Finnex Temperature Controller Digital Heater.

Installing this aquarium heater controller is the same as the previous one. Simply plug in your heater and place the sensor probe into the tank. For the best results put the heater and probe far away from one another so that the probe does not sense the heat of the heater instead of the water. Be sure to adjust the low and high alerts as the factory defaults will allow the water to fluctuate between 67-93 degrees before sounding the alarm.


  • Hold the ON/OFF switch for about two seconds to switch the controller on or off.
  • Use the C/F button to choose your preferred temperature reading of Celsius or Fahrenheit.
  • Pressing the ON/OFF/SET button will switch the controller into temperature setting mode. While the numbers are blinking use the +/- buttons to set your desired temperature. Press the ON/OFF/SET button to finalize your settings.
  • To set the alert/alarm settings press the ALERT-HI/LO button until the temperature is blinking. Use the =/- buttons to set the alert to your desired settings and allow the controller to automatically return to the stand-by state. This will store your setting into the systems memory and will resume after power failures.

This controller can handle all the way up to 800 watts, allowing for one controller to monitor about 270 gallons of water. Once you start breaking past that point you’re pretty much going to have to get multiple controllers or contact an industrial seller.

What sets this controller above the rest is it’s built in alarm system. Once the heat falls or rises past your chosen settings the Finnex will sound, alerting the owner to problems beyond the heaters capabilities. This may not sound that big of a deal but the alarm really does double or even triple the value of the controller. If you are asleep or in another room you won’t notice other controllers small light. A noisy alarm will be the savior to your valuable tank.

In addition to the alarm system the Finnex makes a audible click when the heater shuts off or turns on. This may seem pointless but actually lets you know when there is a lot of temperature change on your aquarium. An example was when my brother turned a fan to face his chair and then turned it away further. The fan ended up directed towards the tank, causing the temperature to fall much faster than expected. Without the constant clicking the heater would have been turning on all day and costing me both money and degrading the heater.

Some of you may be wondering why the controller even has an alarm for the high point. If the controller is powered the heat shouldn’t be able to rise above the set temperature right? Dead wrong. Pumps, Light fixtures, ambient temperature and even filtration can add heat to your tank. When the heater shuts off at only 76 it’s not hard to image a tank continuing to rise above that mark. In fact for the first tank I started in the summer I did not even have a heater in place. The wall would heat my tank to at least 78 degrees with the indoor temperature being set to 75. Adding on large pumps would have easily seen my tank fried! Thanks to the high temperature alarm the Finnex offers your tank will be protected from this fate.

More recently Finnex has added their memory feature onto this model of controller. This means even after a power outage your tank will be kept at the perfect setting, alarms and all still in place.

Once again the warranty on this controller is a solid 6 months. At this price point You will expect the controller to last quite a bit longer than others. Thankfully it does. While my controller still has not broken after six years, the shortest life time I could find was 2.5 years. It’s safe to say this controller will far outlast the competition.

My one complaint with this controller is the probe’s wire length. For being suitable for a 250 gallon the wire should be a little longer. Unfortunately it measures in at about three feet. While the power cord is 6 feet, allowing for a combined 9 feet of cords, the 3 foot probe cord keeps my controller stuck to the side of my tank. It looks really nice and high tech, but I prefer to see the contents of the tank and not the equipment.

By choosing to install an aquarium heater controller you will ensure your tank never meets an untimely end at the hands of faulty heaters or over-heating aquarium pumps. We recommend using only the best aquarium heater you can find for perfect results. While cheap heaters that break and stay on are no problem, heaters that shut off and cannot heat are still useless. Our tanks mean a lot and I certainly sleep a lot better at night knowing my well aged tanks and their expensive livestock are safe and sound thanks to my aquarium heater controller.

Best 30 Gallon Aquarium Heater

Ehiem Jager Aquatop Quartz Fluval E Electronic Heater Aqueon Pro Heater
Price: $$ Price: $ Price: $$$ Price: $$
3 Year Warranty 6 Month Warranty 5 Year Warranty Lifetime Warranty
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Finding the right 30 gallon aquarium heater is essential for our tanks well being. Oversized heaters can quickly fry fish while small heaters will stress fish until they get sick. Likewise unreliable heaters or those with short lifetimes can crash our tanks leaving us with only heartbreak. For this reason I’ve compiled a short list of the best 30 gallon aquarium heaters.

Ehiem Jager 100 Watt

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This is my absolute favorite aquarium heater and is still made by the original manufacturers. If you don’t want to read a whole lot about heaters you will be fine with this guy in your tank.


  • Indestructible Design
  • High Efficiency Heating Element
  • Precise control
  • Multiple Safety Features
  • Long/Reliable Lifetime
  • 3 Year Warranty


  • Older Look
  • Above Average Size

The safety features include shatter resistant glass made from special laboratory glass. The special glass prevents any fissures or cracks in the heater, increases heating efficiency to lower power costs and creates a heat shield. Even when on at full power the Ehiem Jager cannot harm livestock nor will large fluctuations in temperature damage the glass.

I’m not even done with the glass. It is beyond shatter resistant. I have actually had large rocks knocked down by my inverts onto the heater. The heater had no scratches, dents or visible damage and has continued to work for 3 years after the event.

The heater has an auto shut off feature that prevents it from turning on when dry. this is handy during water changes when you move the heater between the tank and bucket or simply when too much water evaporates from the tank.

Setting the heat is done by adjusting the blue wheel. The temperature is printed on the wheel and a red arrow points to the current setting. When the light turns on and off the orange indicator lamp clicks on and off.

Keep in mind this heater measures 12.56″ x 1.4″ making it one of the longer aquarium heaters out there. It can be mounted sideways, which often gives the heater more even distribution, allowing it to fit more easily into our tanks.

Lifetime & Warranty

The Ehiem Jager 100 watt heater has been sitting in my tank for over 5 years. In fact many have reported the tank lasting for 7-20 years with ease! Combining this with the 3 year warranty means your heater will last over 3 years at the minimum. If you register your heater you can even get some special deals straight from Eheim

The failure rate on the Ehiem is exceedingly low, making this the absolute safest 30 gallon aquarium heater. This is largely due to the amazing safety features Ehiem has implemented.

Aquatop Quartz 150 Watt

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The Aquatop 100 watt is the go to low cost 30 gallon aquarium heater.


  • Low Cost
  • Easy To Read
  • Fully Submersible


  • Runs 2 degrees hot
  • Not Exact Settings
  • Difficult To Turn Knob
  • Fragile

Essentially the Aquatop aquarium heater is an introductory heater that measures 10.5″ x 1.5″ x 1.5″. The heater typically runs 2 degrees warm but is fairly constant. Adjust the heat from the lower settings upwards until the desired heat is maintained for perfect use. You can use any thermometer to do this but I always use a stick on thermometer. Take note of what the displayed temperature is incase you ever need to reset the heat. The light on the front of the heater turns on and off when the heater starts and stops heating the water.

To ensure the water is not heater too quickly the Aquatop only heats for one minute at a time. Due to this heating new water before a water change will take a bit longer than usual.

The knob is fairly difficult to turn, ensuring it never changes. However this makes it difficult to turn when wet, which is all the time. As the knob is turned a solid red line moves across the thermometer to display the temperature. Additionally the temperature is displayed above the red bar to help you confirm the setting.

The heating element requires a higher output than other brands of aquarium heaters, which increases the power draw from the tank. Here is some quick math on the increase wattage use:

50 watts x 6-10 hours a day x 365 days a year x $.00012 per hour on average = $13.14-$21.90 extra each year.

Keep this in mind, as the cost will add up over time.

Lifetime & Warranty

The Aquatop quartz 150 watt typically lasts between 1-3 years, a fair lifetime considering it costs half as much as other low cost aquarium heaters. The heater is fairly fragile and cannot be allowed to touch the substrate. Doing so will make the heater prone to cracking and shutting off.

The warranty on the Aquatop Quartz lasts 180 days/6 months. This gives you plenty of time to find any defects with your heater, such as rusting coils on the inside or slowly splitting glass. Be sure to contact the manufacturer as soon as you spot any defects.

Fluval E Electronic Heater 100 Watt

Fluval E Electronic Heater
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The Fluval E Electronic Heater features a different look than most aquariums, along with a slew of features to help make maintaining the tank easier.


  • Digital Display
  • Temperature Warnings
  • Highly Precise
  • Built In Memory Settings
  • Dual Temperature Sensors
  • Protective Case


  • Higher Cost
  • Bulky Design

The main draw to the Fluval E is its digital display and built in features, making the heater into a command center for your tank.

The display will be either green for the correct temperature, red when the temperature is too high and blue when the water is too cool. If the display starts flashing the water temperature is changing too fast. Typically the blue display will solve itself, but the heater cannot cool hot water. If the display stays red for a long time it means the room is too hot or something is heating the water too much. Common culprits include circulation and return pumps.

Additionally if the heater is in a low flow area the screen will display LF. This means you should either direct more flow to the heater or move the heater so that it can dispense heat more evenly

The heat is set by the lever on top of the heater, adjusting the heat in .5 degree increments. If the power should happen to go out this setting will be saved and resumed when the heater regains power. Combine this with the dual heat sensors, which measure the waters temperature rather than internal air temperature, and you have a precise and reliable aquarium heater that holds the perfect temperature.

The casing on the Fluval E heater protects the fish from the heating element while allowing the glass tube full contact with the water. This allows for highly efficient heating while keeping your fish and inverts safe. If you have ever had snails with a glass tube heater you will know just how bothersome they can be. My snails frequently climb on to the warm glass tube, only to let go to avoid burns. This often left them on their backs, killing them if I did not save them.

The heater measures 11.75″ x 1.125″ x 2″ and is mounted by a triple suction cup bracket that can be removed from the heater. This allows for easy cleaning without displacing the suction cups. The suction cups are stronger than the average model and are resistant to warping, but should still be kept clean for maximum staying power.

Lifetime & Warranty

The Fluval E Electronic Heater 100 Watt comes with a massive 5 year warranty, ensuring the heater gives you enough bang for your buck. When combined with this warranty the Fluval should last you between 6-8 years with ease.

Aqueon Pro Heater 100 Watt

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The Aqueon Pro Heater strikes a nice balance between modern design, reliability and low costs for the most balanced 30 gallon aquarium heater.


  • Lifetime Warranty
  • Hardened Plastic, No Glass Components
  • Aluminum Core For Increased Durability and Heating


  • Setting Is Black On Black And Hard To Read
  • Temperature Calibration Is Often Off A Few Degrees

The most notable feature here is the hardened plastic casing that makes up the tube. This is much more durable then even tempered glass, making the Aqueon one of the most durable heaters out there. This however does not enhance the heating element like the Ehiem of Fluval models do, keeping the power consumption normal rather than below average.

The light has two settings of green for off/right setting and red when the heater is on. When removed from water the Aqueon pro knows to shut off automatically and resumes once resubmerged. The temperature is set by turning the large knob on top of the heater. You may need a flashlight as the numbers are black on black, creating a difficult to read surface.

For this heater I would say a second thermometer is mandatory. Unfortunately a fair amount of these heaters ship out with bad settings and will run several degrees off from what is shown. Once the heat is set properly the heat stays on target. Just be sure to let others know your heater is off and not to adjust it themselves.

Lifetime & Warranty

Aqueon features an amazing lifetime warranty on all of their heaters, putting them a step above the rest when it comes to customer satisfaction. simply contact them via the phone number or form shown here. The heaters themselves are also reliable and should last an average of 3 years. You can put to bed the worries of sending for a replacement each month.

After this guide on finding the best 30 gallon aquarium heater you should be more than prepared to make the right choice. Because of the similar size these choices also make great 29 gallon fish tank heaters. If your tank can fit it I cannot recommend Ehiem highly enough, but the other options are still worth considering. If you need a few more options feel free to read my more general Best Aquarium Heater guide.

Best 20 Gallon Aquarium Heater

Eheim Jager 75 Watt Marineland Precision 100 Watt Hydor Glass 100 Watt Aqueon Pro 100 Watt
Price: $$ Price: $ Price: $ Price: $$$
3 Year Warranty Lifetime Warranty 2 Year Warranty Lifetime Warranty
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20 Gallon aquariums fall between small and medium tanks. While it is true they double a standard 10 gallon, they also often introduce larger rocks, more decoration and more equipment. All of these can reduce the actual water capacity, introducing a new element to the fish keeping hobby.

Still with 15 to 20 gallons of water to heat we need a bit bigger of a heater. Thankfully many of the best companies make heaters that are perfect for our 20 gallon fish tanks. I’ll start off with my absolute favorite, which also happens to be the most reliable 20 gallon aquarium heater.

Eheim Jager 75 Watt

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  • Comes In 75 Watt Size
  • Ultra Efficient Heating
  • Extreme Lifetime
  • Specialized Glass


  • Bulky
  • Old Fashioned Look

The Eheim Jager has been one of the best aquarium heaters for over a decade and shows no sign of changing. Made by their original manufacturers in Germany, This heater comes equipped with multiple safety features, accurate temperatures and of course the special laboratory glass casing.

The special glass has three major benefits that other companies can’t seem to figure out. First off is the perfect, fissure and crevice free surface. Any cracks or abnormalities result in a shortened lifespan. Because the Eheim prevents these it will never shatter or crack accidentally.

Furthermore the glass is unrealistically strong. My inverts have, on multiple occasions, caused rock slides to fall onto my horizontally placed heater. Each time the heater showed no signs of damage, even though a couple pieces of the rock chipped off.

The specialized glass also increases heating efficiency to lower operation costs while creating a heat shield. Even while at full power the heater will not harm any live stock, including those curious snails who love climbing all over warm heaters.

Settings & Safety features

Adjusting the Eheim Jager is nothing special. Simply turn the blue ring located on top of the heater to your desired temperature. There is a red arrow pointing at the wheel, making it easy to set an exact heat

Should the heater come in contact with air, either from water evaporation, water changes or moving the heater, it will shut off automatically and resume upon being fully submerged. This helps prevent any heater explosions, which are a real danger not to be taken lightly. I’ve had a cheaper heater shoot shards of glass at me when I was carelessly heating multiple buckets of water.

When the lights orange light turns on the heater is currently heating the water. This makes a light clicking noise. The Eheim Jager 75 watt measures at 10.63″ x 1.42″ which is a little long for a 75 watt heater. So long as it fits in your tank this is may top 20 gallon aquarium heater recommendation.

Lifetime & Warranty

When it comes to warranty Eheim takes all matters seriously and is happy to help. They feature a solid 3 year warranty and stand by it.

You likely will not need the warranty however, as the Jager has the lowest failure rate of any 20 gallon aquarium heater. Given normal circumstances the Jager at least 7 years, with many users reporting 10+ years and a couple at 20. Mine has been going for over 5 years and still looks/works like new. This is seriously the most dependably medium sized aquarium heater.

Marineland Precision Heater

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  • Comes In 75 Watt Size
  • 1 Degree Increments
  • Easy To Read
  • Powerful Mounting Bracket
  • Efficient Heating
  • Lifetime warranty


  • Shorter Lifetime (1-2 years)
  • Light Outlasts Heater
  • Can Trap Bubbles

Marineland, not exactly the brand you think of for heaters and more for the rest of the tank. However this low cost 20 gallon aquarium heater really brings a lot more to the table than expected.

Setting the temperature with the Marineland is easy, as each click changes the heat by 1 degree. This activates the mica core, which is surrounded by a mesh barrier that helps transfer heat and increases structural integrity. The heat settings range from 65 to 89 degrees.

Setting Up & Safety

Mounting the Marineland Precision heater is a bit different, as the three suction cups are attached to a mounting bracket. The heater rests inside this rather than having the suction cups directly on the heater. This gives a bit more exposure to the heater while keeping the suction cups more stable.

When first submerging the heater and bracket, rotate the two separately and release any and all air bubbles that may be trapped in the two. These can cause premature damage otherwise. This does not mean you cannot place the heater near bubbles, ad the trouble maker bubbles are only located deep in the heater.

This 20 gallon aquarium heater is fully submersible and comes with a 6 foot power cord, easily letting you hide the heater while still forming a drip loop with the cord. The heater is 10″ long and should not be touching the substrate.

The Marineland Precision heater features a thermal fuse which will shut off the heater when exposed to air. This keeps the heater safe when doing water changes or when moving it around.

Lifetime & Warranty

The Marineland precision heater lasts between 1-2 years, which is pretty good at the amazingly low price. After the heater gives out you can use the lifetime warranty by contacting Marinelands support at 1-800-322-1266. When you call you will need the code on the back of the rubber cap where the dial is. With my lights I have always received excellent customer service from their representatives, making Marineland my favorite on warranties.


The Jager and Marineland are special as they are the best heaters to come in a 75 watt size. The 100’s listed below are 100% safe, but they can cost a bit more to run.

Hydor Theo Submersible Glass Aquarium Heater

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  • Easy To Hide Colors
  • Strong Suction Cups


  • Does Not Come In 75 Watts
  • Weaker Heating Element
  • Medium Lifetime

The Hydor is a fairly low cost heater that does exactly what you expect with a few downsides. Most notably it does not work well in cold environments and costs a bit more to run.

Set Up & Safety

Located on the top of the heater is an extra thick rubber top. This is in place to prevent any shocks caused by light cuts in the heater. On top of that is the easy to read red dial, which ranges from 67 to 91 degrees Fahrenheit. Because the heater is a little weak I highly recommend using a second thermometer to keep an eye on the tanks temperature. Cold houses may need to set the heater much higher than actually needed, or choose a different heater entirely.

The heater is mounted by two suction cups, which have pretty solid grip. This is nice for mature marine tanks who’s walls often have coralline algae and need extra grip.

The big plus for the Hydor Theo is the extra compact design. The 75 watt is just under 9″ which allows us to use this in nearly any sized tank and easily hide it behind rocks or plants. This is a great plus as it gives the tank a more natural appearance than other heaters.

While the heater does say it shuts off when it is dry many users have not found this to be the case. Take a little extra caution here and treat the Theo as if it does not have auto shut off.

Lifetime & Warranty

The average lifetime for a non defective Hydor Theo is 2-3 years, Combined with the two year warranty gives you an average of 2-5 years of lifetime. This is the shortest of my recommended heaters, but the Theo has its own special merits.

The warranty is not as easy to use as the other heaters and requires a bit of emailing around. Expect this to take 2-5 days.

Aqueon Pro Heater

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  • Lifetime Warranty
  • Hardened Plastic, No Glass Components
  • Aluminum Core For Increased Durability and Heating


  • Setting Is Black On Black And Hard To Read
  • Temperature Calibration Is Often Off A Few Degrees
  • Does Not Come In 75 Watts

First let me give you a warning. Aqueon does sell a cheaper glass heater, however it is made in china unlike this one which is made in Italy. While some made in China products are amazing the cheaper version here is not.

Anyways the Aqueon Pro heater is a fantastic piece of equipment any aquarium would be happy to have. It features a strong, hardened plastic casing which makes it completely shatter proof. At best you will manage to scratch or dent the heater over the life of your tank.

Inside the heater is the aluminum core, which both increases heating efficiency while also increasing durability. The hardened case wouldn’t mean a whole lot if the insides constantly broke.

The two nice features on the Aqueon pro are its red and green light and auto shut off feature. When removed from water the heater will shut off automatically and resume when resubmerged. Fairly common in most heaters but it’s still nice to be sure. The lamp will either show green for correct temperature/off and red for low and on. Very few heaters actually have the confirmation light and simply switch off.

The two big draw backs are the black numbers on a black surface and the accuracy of the heater. When setting the heat you will either need a flashlight directly on the light or to have the heater directly under your lighting fixture.

As for the temperature accuracy the Aqueon Pro is often off by +/- 2 degrees, meaning you will need a second thermometer to set this heater. Adjust the heater until you have the right temperature and you’re good to go.

Lifetime & Warranty

With the average lifetime of the Aqueon pro being just above 3 years you should more than get your moneys worth from a single heater. This however will not be the case thanks to Aqueons lifetime warranty. Even if you get the golden heater that dies after 30 years Aqueon will happily send you a replacement once the heater does die off. No more looking for purchase dates with this heaters warranty.

Looking for other ideas on aquarium heaters? check out my more generalized page on the best aquarium heaters.