Comline DOC Skimmer 9004 - Tunze

Tunze Comline DOC Skimmer 9004
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Comline DOC Skimmer 9004 - Tunze

100% Recommend this to a friend (12 of 12)

SKU: 208412
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Quick Overview

Why does BRS recommend this?

We have really liked the Tunze Comline skimmers due to their small form factor and their ability to adapt to many different systems. With AC pump and DC pump models available you can choose the skimmer that works best for your system.

Using the Tunze Flash Skimming Principle, the Comline DOC Skimmer pulls water through an efficient surface suction.

Heavy Bioload - 20 gallons

Medium Bioload - 40 gallons

Light Bioload - 60 gallons

  • Up to 65 Gallon tank (Depending on tank load)

  • Skimmer Cup volume: .2 Liters

  • Air capacity: 40 GPH

  • Magnet holder for up to 1/2" thick glass

  • Quiet Operation

  • Bubble free outgoing water

  • Easy to remove collection cup

  • Immersion depth: approx. 225mm to 245mm (8.86 to 9.65 in.)

  • Power consumption: 4W, 230V/50Hz (115V/60Hz)

  • Dimensions: L110 x W90 x H305mm (L4.3 x W3.5 x H12 in.)


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Product Questions

hey guys! im planning to set up a 60 gal reef tank with some nice corals, anemones and clown fish and others... i don't know which skimmer will fit best...

Tunze Comline DOC Skimmer 9004 or Reef Octopus BH2000

what would you guys recommend buying?

thanks a lot

Question by: ViKo on Jul 10, 2014 9:06:00 PM
Hi ViKo,
If it is between these two skimmers my preference is for the Octopus. I really like the Tunze skimmer it just happens that the Octopus is rated for a much larger tank and when it comes to skimmers, I would always get the biggest one that fits in your budget and space constraints.
Answer by: Bulk Reef Supply on Jul 10, 2014 9:06:00 PM
Will this fit on my Coralife Biocube 14?
Question by: Ryan on Nov 4, 2016 10:50:00 AM
Hey there! Unfortunately, this will not fit in that BioCube chamber. :-(
Answer by: Randy (Admin) on Nov 4, 2016 12:18:00 PM
Would this skimmer be sufficient with the Fluval M60 AIO aquarium?
Question by: Zak Payne on Jun 13, 2016 9:29:00 PM
Great question!
This will be a great fit as far as performance of a system of that size! You will want to confirm that the skimmer footprint will match the tank.
Answer by: Connor (Admin) on Jun 15, 2016 2:12:00 PM
Will the 9004 fit in my IM Fusion 40 gal.
Question by: Capt. Sergio Atanes on Jan 26, 2016 5:43:00 PM
Great question!
The 9004 will just fit in the overflow section however this will restrict the overflow compartment as well has having height issues. While it may work we recommend the IM midsize ghost skimmer as an alternative which is designed for the tank. Feel free to let us know if you have any further questions!
Answer by: Connor (Admin) on Feb 3, 2016 3:31:00 PM
My skimmer was doing well for about 8 months and then started acting very funny after a water change during which te skimmer was temporarily turned off. The problem is that micro bubbles are pouring our of the bottom and the collection cup fills with water almost immediately. Adjusting the air hasn't yielded good results. Any suggestions?
Question by: William Moss on Feb 9, 2016 10:22:00 PM
Great question,
Some quick fixes may include changing the height of the skimmer in the water. Making sure no other changes have occurred as well such as different bio-load or other adjustments to the skimmer cup itself. Feel free to let us know if you have any further questions!
Answer by: Connor (Admin) on Feb 10, 2016 12:46:00 PM
Would this fit in a nuvo 30L?
Question by: Eric on Feb 1, 2016 1:23:00 PM
Great question!
The Tunze skimmer actually mounts from the side and would not fit well by mounting it in the tank. Ideally the Midsize Ghost skimmer by IM is the ideal shape and size for your tank. Feel free to let us know if you have any further questions!
Answer by: Connor (Admin) on Feb 19, 2016 9:33:00 AM
I didnt actually mean to buy this skimmer but if it works in my Coralife biocube 29 I will gladly use it. Any idea if it will fit in my biocube 29?
Question by: Dave on Apr 20, 2016 7:16:00 PM
Great question!
Unfortunately we do not have the dimensions of the Coralife tank however the skimmer dimensions are (L4.3 x W3.5 x H12 in.)
Answer by: Connor (Admin) on Apr 26, 2016 2:21:00 PM
Will this fit in in the back of a Nuvo 16?
Question by: Brian on Apr 27, 2014 7:24:00 AM
Hi Brain,
Unfortunately it would be too large to fit in the back of a Nuvo 16.
Answer by: Bulk Reef Supply on Apr 27, 2014 7:24:00 AM

Full Details

Owners Manual


The Tunze Comline DOC skimmer utlizes Tunze's "Flash Skimming" principle. The skimmer is quiet and generates a very large volume of small bubbles for efficient skimmer operation. It operates stand-alone without needing any additional equipment (feed pumps, etc) and mounts to the tank via a convenient magnet holder strong enough for glass up to 1/2" thick.

The TUNZE® Foamer generates large volumes of fine air bubbles with a diameter between .0039 to .011 in. (0.1 to 0.3 mm) On the surface of the air bubbles, pollutants such as protein, cellulose, dead cells, etc. are adsorbed immediately. The water/air mixture expands and stabilizes in the skimmer cup reactor, the water returns to the aquarium, and the protein-loaded air bubbles spill over into the skimmer cup. The patented anti-overfoaming system intermediate chamber prevents the skimmer from over foaming and controls the skimmer performance, depending on the water level and organic load. This “flash skimming” principle, compared to large skimmers with long contact time, is obtained because the substances adsorbed by the air bubbles are not released again, thus they don‘t return to the aquarium water.



12 Items

  • Worked like a charm By Alfred on 12/13/2016

    I bought a complete reef set up that came with a skimmer but alas, it was giant for this small 30gallon (sump included). I finally decided to throw the money at a new one and this one offered the perfect space saving to proper skimming ratio my tank needed. It fits nicely into my small sump and even leaves room for me to integrate a tiny refugium. To add to it, it skims great and my corals look happier than ever
  • Great protein skimmer By Matt on 9/23/2016

    I needed a protein skimmer that did a good job, wasn't too expensive, and was quiet due to the fact my tank is in my room. I was not disappointed.
  • Best Nano Skimmer I've Used By Andrew on 6/9/2016

    I have been using this skimmer on my IM Nuvo 38. I switched from the IM Aqua Gadget skimmer I had on this tank. The Aqua Gadget skimmer required constant adjustments. This skimmer is working great, hasn't needed any adjustments after the initial setup and is quiet.
  • Big Power in a Small Package By Chris B on 5/6/2016

    I have a 58 gallon Oceanic tank which is basically a tall 40 gallon footprint. Because of this size restriction I initially was running a BH1000 Reef Octopus hang on skimmer that just killed the aesthetic of the display portion of the tank, even if it was working great, it had to go. With the small size of the Tunze, I was able to put this in my sump which is otherwise devoid of space for a traditional skimmer. Although I am at the very top if not exceeding the size rating of this skimmer, I am running a relatively low nutrient system, but not ULNS by any means, with 6 fish and full CUC that is fed well daily. This skimmer is doing a great job all around. It took only about 2 days to break in fully, 3 days to tune, and pulls great skimmate consistently. The footprint compared to performance is amazing. The only minor complaints are in the reassembly after teardown and how short the breather line is. I wish it was set up for another 3-5 inches to place in comfortably out of my sump chamber. I could extend it, however they recommend against it, and I haven't had time to tinker yet.
  • Great By Kevin on 2/16/2016

    Best nano protein skimmer I have ever purchased. I am using it on my JBJ 30g rimless and fits perfectly into the first chamber. Does an awesome job!
  • Great product. Some minor issues By Dhero5 on 1/12/2016

    When I received the product I followed the instructions which were pretty straightforward and simple. Once I plugged it in nothing happened. I did a little research and found out it's very common for the hose disconnects from the pump in shipping. I took the device apart and sure enough that is what happened. I put back in the tank and it worked except I had a ton of micro bubbles in the tank. I did some more research on the position of the pump since the book doesn't explain how it should be positioned. I found a picture thT shows the pump attached to the front cover which made sense and worked. The pump has been operational for 2 weeks. I still have some bubbles but that is expected since it is in the tank. One problem I noticed out of the box was the magnet extenders are cheaply fastend to the body by clips. One clip arrived broken and the other ended up breaking so they are glued to the body now. The magnets are not as powerful as I expected so they do both old the unit super solid but it works.
  • Perfection By Brett on 8/20/2015

    This is on a JBJ 45 gallon rimless aquarium with the AIO sump on the back. Fits like a glove. Works amazingly.
  • Nice small internal skimmer By Smulemkr on 7/12/2015

    I'm using this skimmer in my 60 gallon quarantine tank- works very well.
  • Great Skimmer By Greg on 3/26/2015

    I have been in the reefing hobby for approximately 15 years and have used numerous products for my tanks. Tunze products have always been great for me. I recently bought a Fusion 40g and after much research for different brand skimmers I again chose Tunze. The Tunze 9004 skimmer I purchased has been excellent. I have read a lot of reviews from others about how the skimmer is difficult to reassemble after cleaning. I have not had this problem but maybe I have been lucky. This skimmer does a great job and my tank looks excellent. I have however had to make some small adjustments to the air valve during it's break in period but once tuned it is perfect. The advertisement for this skimmer states that it can handle aquariums in the 65g range but have not tried it personally so can't comment whether it can or can't. I know that there are more expensive brands that can be used for my size tank but chose Tunze instead and am glad I did. This skimmer is compact, virtually quiet during operation, and has the ability to handle a decent bioload as well. Does that mean you can house ten or fifteen 4" fish in a 30 or 40g tank when using this skimmer? In my opinion no and I don't think it should be tried. With common sense, a sensible amount of livestock, and frequent water changes this skimmer In my opinion will do everything it is advertised to do. Happy reefing!
  • Great skimmer! By Cristina on 2/13/2015

    I have a Innovative Marine 39g tank. The space in the back of the tank designed for skimmer and other gadgets is very tight and pretty hard to find a good right size skimmer. I tried ,Innovative Marine ghost skimmer medium size (that is so little it went completely under water) , Hydor nano skimmer medium size (did a horrible job), CPR bak-pak skimmer (my original skimmer) which was ok but the pump kept breaking and it was sooooo loud! In the end I decided to go with this skimmer and man am I so glad. It is super quiet! It seams to be doing its job (just install it so can't give much review about how good of a job it is doing). I get no micro bubbles (some reviews were saying it does produce micro bubbles). The magnets I would say are not to strong which many do complain about but if you are careful then you can work it out very well. In all I absolutely LOVE IT! The best investment so far! I wish the collection cup was a bit bigger though but not a big deal, I guess I can empty it more often.
  • Works, but could be built better By DrexelLake on 12/12/2014

    I have the same complaint as many reviewing this online, and that is that it very flimsy and hard to get back together. The bubbles do come out all over too, but that doesn't make it less effective. Works great until you need to clean it. It took me 20 minutes to get the snaps to hold when putting it back together.
  • Great skimmer for small tanks By Clint on 4/11/2014

    I have been using this skimmer in a 20 L for about a year and have been very happy with it. It does not appear to be very sensitive to changes in water level, produces good skimmate, is easy to clean, stays in place with the magnets. If you are willing to sacrifice a little space (the skimmer sits inside of the tank) I think this is a great choice for tanks less than 30 gallons.