Worked well at first but eventually it needed cleaning about once a month because the airline gets clogged. It just suddenly stops working completely. It’s very difficult to get the outer housing back together so I dread cleaning it. After a few years of this I’m going to get something else because it’s just too annoying.

The skimmer itself works pretty well but I dread cleaning it. It takes forever to get back together and it always leaks bubbles as I can never get it to completely pop closed.

Like mentioned above in another recent review, horrible warranty work. I'm now a week without a working skimmer while the replacement part is in the slowest transit possible. Also, I'm not even confident this will repair it for the long haul. This is a brand new unit that failed 10 days into using it. Unfortunately it was out of the 30 day BRS warranty, but I'm sure it could have still been handled that way. BRS and Tunze won't be seeing any more of my money, nor will I recommend either.

I have had this unit for 6 weeks, then it started making clicking noises and not working. I called BRS support and was directed to Tunze support. They will only Email you, also they will not replace the unit, instead I had to disassemble the unit and send multiple videos. This process took several days, finally they determined which part they would send me. It has been 2 weeks since I started the process and the piece still hasn’t shown up! They sent it using USPS (slow) and didn’t even expedite the small package (Thanks for the effort). When I expressed my concern about the welfare of my livestock without this life support item, the answer was to under feed and do lots of large water changes. I find that answer to be the most expensive and labor intensive way! I hope the piece that they send is the actual fit but I’m not sure that they care.

This is my first skimmer. It was very easy to set up and get running and is not intrusive against my black background. The skimmer started skimming pretty much immediately and collects nasty stuff I clean out every couple of days. I started with a low setting and then gradually turned the power up. I have no ATO, but so far (after about 4 months) had no issues with having to adjust the skimmer due to changing water levels (I do have a lid, not mesh). The airline did get clogged after about 3 months, but was easy to clean. While I cannot compare it to other skimmers its ease of installation and silent operation make it a good product in my opinion.

This skimmer is decent. It gets the job done and works well in smaller tanks. It's quiet, will produce good skimmate, and works great as long as you make sure the waterline is sitting on the marked waterline on the back of the unit. One thing that isn't obvious is that the unit is not really meant to be placed in a sump unless you have a fairly deep sump. It needs to sit a half inch or so above the bottom in order to pull water in and can't sit on the bottom like a traditional skimmer. The mounts are definitely somewhat junk, but they work. As long as you are kind to the unit, they don't magically pop off, but they aren't as stable as I'd personally like. They do tend to pop off when you remove the unit for cleaning, but they do pop back on again without too much of a fuss. It does suffer from salt creep issues in the air tubing, so know that you will have to take this apart and flush the tubing every month or two. It doesn't come apart and go back together super easily, so pay attention when you put it back together as any seams partially open will cause it not to work. I personally haven't had issues with microbubbles with this guy, but I also have it in the first compartment of my sump where the water has plenty of time to circulate before being sent up to the display.

This was my first skimmer and I read that it may be finicky with water level. But I had no issue setting it up and getting it to work (without an ATO). I had very little microbubbles for a couple of days and the DC model is easy to adjust. It does produce bad smelling dark skimmate, so it seems to work. I have it directly in the DT, but as I have a black background it is not too intrusive.

I don't recommend this skimmer for a JBJ RF-45 AIO tank. It fits in any of the slots in the rear sump, but it just doesn't skim well. It's a surface skimmer and is not very efficient when confined in a small space. I tried using it for over a month at different heights and different pump speeds. It had good foam height, but it would only produce greenish/clear skimmate. I only have three small fish. Even after reducing feeding and increasing my weekly water change from 12% to 25%, my nitrate increased from 1-3 to 5-10+ and phosphate increased from 0.02 to 0.06 before I stopped using the Tunze. I had my first hair algae outbreak since starting the tank 14 months ago. This skimmer might work well in a different situation, but not in an AIO chamber. It's a shame, because the form factor is perfect, and it looks very clean. Tunze is still a good brand, and I use several of their other products with great success. I went back to my CadLights (now Mode Aquariums) PLS-50 Elite II skimmer. It's an eyesore and sticks out of the tank, but it pulls thick brown mud out of the water and keeps nutrient levels low. Their customer service is terrible/non-existent, and the pumps only last about a year, but the performance is substantially better.

I've been reefing for 20+ years and most of my skimmers have been Tunze. None have let me down and all have worked as expected or better. This one has been just the same as all the others. It's the perfect skimmer for the nano quarantine tank.Barely audible.

This skimmer is super quiet, easy to tune, and started skimming within the first day. Great skimmer for my 32 gallon display with 20 gallon sump.

We purchased this skimmer for our mini tank build to replace the factory skimmer that was provided with the tank from Fluval. I have to say that the difference between the two skimmers is night and day. Our tank is so much cleaner and the nutrient levels have been cut in half. We are completely happy with the skimmer so far.

The good: Skims well for a small skimmer. Easy to adjust with controller. Has a button to stop the skimmer and auto restart in 10 minutes. You can disconnect the power plug from the controller rather than unplu the power plug if it is easier to reach and not have to reroute the plug again to reconnect. Cup is just a lift off to clean. The bad: they include optional spacer not installed to move the skimmer box further away from the back wall if your tank rim is wider than normal. Most likely you won’t need these. I made the mistake of using them. To use them you need to remove the magnet from the box which for some reason is almost impossible when it’s new so you end up breaking off the retaining tabs. (Tunze knows this and will warranty the back panel) this spacing causes a new problem. My snails go behind the skimmer and knock it off the magnet to box connection. This is the spot that was impossible to take off which now comes off too easily for some reason. The magnets that hold the skimmer are very strong which is great. The issue is that on a thin glass tank it is impossible to remove the magnets unless you have dirty glass to lessen the connection. Now that you finally removed the outer magnet the inside one still has a suction effect that is very difficult to remove. Fortunately the box falls off the tabs mentioned previously which allows you to remove the box easily. The mounting system is poorly designed in my opinion. The other issue with removal for cleaning is that the controller does not disconnect from the skimmer pump. So you’ll end up dragging that around behind your dripping skimmer box. Once you get the box out I suggest soaking it completely in an old salt bucket filled with vinegar. The box snaps together and feels like you’ll break it trying to disassemble but you won’t break it. Pay attention how it went together because it’s not obvious where the divider pieces go until you look at the slots cut into it. It will not snap together unless they are properly placed. It does come completely apart which is great for cleaning. As much as it stinks to take apart and clean it is still a great skimmer I wish Tunze thought out the mount better and made disassembly a little less difficult. I dread cleaning this and that always reduces how often equipment gets properly cleaned.

Airline clogs on all the 9004 skimmers. Purchased this doc skimmer as my previous was a regular 9004, thinking the airline wouldn’t clog anymore. This one still clogs up, requiring you to remove the skimmer and take it apart to clear the airline of salt creep. This happens once a month at least. Tried contacting Tunze and they are useless about this. Knowing this is a engineering flaw in their product and not addressing it. Not only not addressing it, but continuing to sell this.

My wife wanted a small 35 gallon FOWLR set up in the family room as the 150 gallon in the living room was too large. This 9004 DC is outstanding. The little pump that could. Almost unnoticeable and so quiet. Began foam production almost immediately with skimmate later in the day. Once the unit is placed in the tank, a quick adjustment of the DC pump where you want the foam line, you done. No micro bubbles at all. Well worth the money. Would recommend.

This protein skimmer, works so well as it is actually skimming the heaviest protein scum in your actual DISPLAY tank. Most other protein skimmers sit in the sump which receives proteins diluted in large volumes of churned up water. Probably takes a few more trips visiting the sump to clear it out, if ever. I bought this for my 35 gallon next to my family room TV as stated in my previous review, quiet! When my other tank, 150 gallon, needs a new skimmer, will definitely use Tunze larger Skimmers!

Once installed the skimmer instantly started producing skimate after a week worked even better. Very impressed and worth every penny to improve water quality.

This skimmer is great.It started producing skimmate in less than 30 minutes.This skimmer is awesome with the DC model. You might be thinking it so expensive, But this has cut my algae in half. It's very cool with the cup collection feature.The only downside is that tiny micro bubbles slip through the collection cup and the main unit but its very minimal. Hope this helps.

So I have this skimmer in the Nuvo 40 and I absolutely love it I have it in the first chamber and it does restrict some flow but it worth it. It's been in tank for about 24 hours and already has some dark nasty skim mate in the cup. It's super quiet can't tell it's even on I hear my return pump over this skimmer. I picked up the one that you can control and I am glad I spent the extra money for it well worth it. Don't worry about this buy you will love it. Thanks BRS for carrying another awesome product .

Fantastic skimmer! I purchased this skimmer slightly oversized for my tank (29 gallon) primarily due to the adjustability for bioload and surface skimming capability as I don't have a sump. Could not be happier. Pulls out some nasty gunk. Don't worry if it is a little noisy initially, once it breaks in the skimmer is practically silent. Thanks BRS for carrying Tunze skimmers...

Purchased this for my JBJ RL30 and live the sludge it's pulling from my tank. Very impressed with the dark skimmate from a nano sized skimmer. The DC motor allows for true adjustment to fit your bio load needs. Another great product from a trusted brand.

My second one, another great product from Tunze. works great and is easier to control the air for a nice DRY skim. Plus it can be hooked up with safety box to make it battery operated in a power outage.