Tunze 9004 Protein Skimmer Review

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Tank Size Noise Level Longevity Price
Up to 65 Gallons Very Low 3-5 Years Medium-High

The Tunze 9004 Protein Skimmer offers excellent filtration in small spaces without being difficult to use. The set-up process is a few minutes tops, with a couple adjustments throughout the first day. Once in place the skimmer will start to filter out any organic debris from the tank, preventing them from corrupting your aquarium with dangerous ammonia and nitrites.


Note: Many users have reported the same issue, where the air tube inside the Tunze protein skimmer is disconnected. This will create a lot of bubbles, increase the noise of the skimmer and make it almost useless as a skimmer. If you see these issues open up the skimmer and make sure the air tube is attached before resubmerging it. If you have not submerged it you may want to check before doing so.

The Tunze 9004 Protein skimmer has only two real requirements.

First the grate located near the top of the skimmer must be partially submerged. The skimmer should be deep enough to prevent micro bubbles from forming, without being so deep that the skimmer is flooded with water.

Use the provided magnets to hold the skimmer in place. When doing this always press the magnet into the glass above the skimmer and slide the magnets down into place, opposite the skimmer’s glass wall. Make sure to keep the magnets separate! They are very strong and can be difficult to separate without a work bench. Also ensure you do not place your fingers between the magnets.

Once you have the skimmer in place you may plug it in and turn it on.

The skimmer should produce a fair number of bubbles now. You will need to use the tube attached to the back of the skimmer to dial the bubbles up or down. This part is labeled 6 on the diagram on the right. You will want the bubbles to come part way up the top of the skimmer’s cup. This will let the skimmers bubbles pop near the top, pushing the organic materials and a small amount of water into the skimmer’s cup. The more bubbles you let reach the cup the more frequently you will need to clean out the cup.

For a good skim you should be getting fairly green water. If your tank is rarely over fed it may only be slightly green, however many reef tanks will get a sludge like consistency from their skimmer. This frequently happens from the excess foods the water holds for corals.

The cord is about 2 meters long.


Protein Skimmers are typically disassembled and cleaned on the inside once a year, or if they become less effective than usual. Thankfully the Tunze 9004 Skimmer is easy to disassemble.

To start remove the skimmers cup and unplug the skimmer. Next loosen the latch hook from the cover. This shouldn’t take too much force, but it wont come off right away either.

Next loosen the latch hook from the skimmer panel and open the housing by applying pressure to the sides of the skimmer. Now remove the foamer from the place and disconnect the air line from the foamer.

The skimmer should now be disassembled and can be cleaned out thoroughly. Use tank water to rinse off the skimmer and paper towels for any scrubbing. You want to be sure you are not using anything that has come into contact with cleaning solution.

When you have finished re-assemble the skimmer in reverse order before restarting it. Take a minute or two to ensure you have the skimmer the right depth and the bubbles at the right strength.

If the skimmer is producing a lot of micro bubbles you may need to squeeze it shut a bit tighter.

Warranty & Lifetime

Tunze provides a two year warranty on this particular protein skimmer. Be sure to keep the packaging tucked away somewhere, as the manual states this is needed. This has not been the case when I have dealt with Tunze’s customer support, but it’s better to be safe than sorry.

Most users will see well over two years of lifetime from this skimmer. When it does stop working you typically only need to replace a part, which is often under $15. Simply contact Tunze to make sure you are replacing the right part.

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