Hydor Koralia Magnum Powerhead Review

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Size Dimensions Tank Size Noise Level Longevity Price
1650 GPH(Magnum 5) 6.5″ x 4″ x 4″ 60-130 Gallons Very Low 3-7 Years High
2250 GPH(Magnum 6) 6.5″ x 4″ x 4″ 75-170 Gallons Very Low 3-7 Years High
2750 GPH(Magnum 7) 6.5″ x 4″ x 4″ 90-200 Gallons Very Low 3-7 Years High
3250 GPH(Magnum 8) 6.5″ x 4″ x 4″ 110-240 Gallons Very Low 3-7 Years High

The Hydor Koralia Magnum brings the strength and quality that Hydor is known for, but introduces dual current to the brand. This creates a much quieter startup which is what hindered the previous models. Wave makers are no longer an issue for Hydor.


Given the power and size of this powerhead, Hydor had to add a bit more strength to the mounting system. A magnetic suction cup base goes on the inside of the aquarium, while a strong, exterior magnet helps hold the Magnum in place. In general this will do the trick, but for quick, short waves that hit 5 seconds or below, it can still slip over time. You may need to go to the next speed setting on your controller to ensure this doesn’t happen. The magnets are rated to work for glass up to .8″ thick.

The body is already set up when it arrives, but can easily be disassembled and reassembled using the diagram below.

The grates on the side of the powerhead are fairly small and protect the fish from the propeller. The fronts openings are not quite as small, but the flow will keep out any fish. When shutting off and restarting the powerhead, ensure no small fish or fry are near the front of the powerhead, as they may dart in when you reach for the power.

An additional note on fish safety is there is no risk of reverse running. This is thanks to the dual current, which ensures the motor starts the right way every time.

The overall body of the Magnum is much bigger than most powerheads I am used to using. It is easily noticeable in even large aquariums and is difficult to hide. The flow it provides can easily replace multiple powerheads, so this can be the trade off. Less powerheads but one big body.

The cord is the standard Hydor 6′, which gives you an ok amount of wire to use. For the bigger models, and therefore bigger tanks, you may have issues getting the powerhead where you want it.

Special Note: An odd, but useful feature has been created for the Hydor Koralia Magnum known as the AHS or anti heating system. If the motor fails to start three times in a row power to the powerhead will be cut. This prevents pointless power being used when the propeller cannot spin and protects the powerhead from itself. To fix this you will need to clean out the inside of the powerhead and restart the powerhead.


The Hydor Koralia Magnum comes apart at the middle of the body, exposing the propeller. While the propeller does come out, it brings with it a long bracket, which is used to keep the propeller in place. This protects the propeller from the grates and reduces the overall damage it will see.

Once you have removed the propeller you have access to the propeller mount. Keep in mind that both the propeller and propeller mount have magnetic components. These must be cleaned using soft materials, such as a cotton swab. Any rough materials can damage the magnets, causing irregular spinning. Thanks to the bracket this will not cause much damage, if any, but the power may be reduced.

When reassembling be sure to put the propellers protective bracket in all the way and screw it into the mount.

Finally there is an included wire protector in the Hydor Magnums box. This is for creatures who can damage the cord, such as urchins, triggers, puffers and parrot fish. Coil it around the wire to secure it in place.

Flow & Adjustments

While the new DC allows for easier use with wave makers, the flow rate is still unadjustable. This does not stop the powerhead from making waves, but it does not give you complete control over your tanks flow.

The direction of the powerhead is easy to choose using the ball mount and can be pointed any which way. I do not suggest pointing the powerhead at too much of an angle, as the magnet may fail if the powerhead is pushing too far in any one direction. Remember: sliding magnets apart is far easier than pulling them apart.

As the flow is not adjustable and the Magnum only comes in large sizes you will need to find either a different model or brand of powerhead for less flow. At this price range I’d recommend looking to Tunze for the smaller sized powerheads.

Warranty & Lifetime

Hydor provides all of their powerheads with a two year warranty. Given the 3-7 year lifetime on this powerhead it can be either just enough or slightly too short depending on your luck. Most faulty models will be found in this two year periods, with most of the faults being noticeable on day one. If the powerhead does fail after the warranty you should still contact Hydor. They are quite friendly and will help you as best they can. Just because the warranty ended doesn’t mean you aren’t a valued customer to them.


The Hydor Koralia Magnum is a powerful, quiet yet big powerhead. It can easily keep even larger tanks well circulated and comes with plenty of safeguards to ensure a longer life time. Hydor products are high quality, and the Magnum certainly showcases it.

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