Recommended for marine aquariums up to 250 liters (66 USgal.).

Immersion depth of 80 to 250 mm (3.1" - 9.8 in.) without setting.

Dimensions without post-filter (L x W x H): 190 x 190 x 330 mm (7.5" x 7.5" x 13.0")

Water flow rate: max. 850 l/h (225 USgal./h)

Air flow performance: 150 l/h (39 USgal./h)

Power consumption: 8.5 W, 230V/50 Hz

Skimmer cup volume: 0.2 liters (6.7 fl.oz.)


How do you select the right DOC skimmer for a marine aquarium?
Due to its biotope composition, every marine aquarium has a different sensitivity with respect to the organic load. Based on a standard marine aquarium with leather corals, the data on the suitable aquarium size may differ for other biotope compositions. For this reason, the aquarium volumes recommended for the skimmer should be reduced for more sensitive biotopes, if and when necessary.


Low sensitivity, no reductions
In...
leather coral aquariums with long-polyp corals and anemones, for example, the load of dissolved organic matter may be higher, sometimes it may even be vital.
The DOC Skimmer can be used for the recommended aquarium volume without reductions.

Average sensitivity, 40% reduction
Amedium organic sensitivity is usually found in mixed aquariums inhabited with leather and stoney corals (LPS). Filters, sponges, etc. can also be found there. A DOC skimmer that is designed for 1,000 liters (264 USgal.) is likely to only skim 40% of organic substances with this light pollution.
Thus, a DOC skimmer for 1,000 liters (264 USgal.) should be used for a tank with a maximum content of approx. 600 liters (158 USgal.).

Increased sensitivity, 60% reduction
Aquariums with primarily small-polyp stoney corals (SPS) require an especially high degree of purity. They should have no load of phosphates or nitrates worth mentioning. Good oxygen saturation and very clear water are the pre-requisites. In this type of aquarium, the DOC skimmer is frequently used as a "stand-alone solution".
Thus, a DOC skimmer for 1,000 liters (264 USgal.) should be used for a tank with a maximum content of approx. 400 liters (106 USgal.).

High sensitivity and high load,
70% reduction
Hard coral aquariums (SPS) with a high population of fish require an extremely high skimming capacity. The skimmer has to ensure the proper degree of purity for hard corals in case of an excessive fish burdening, whereas an especially high performance is required if it's used as a "stand-alone solution".
Thus, a DOC skimmer for 1,000 liters (264 USgal.) should be used for a tank with a maximum content of approx. 300 liters (79 USgal.).

Especially for Comline DOC skimmers used as contact skimmers for breeding tanks with plankton, 70% reduction
Stone coral aquariums or other breeding tanks with plankton food require an especially high degree of purity. Good oxygen saturation and very clear water are the pre-requisites.
Thus, a Comline DOC skimmer for 1,200 liters (317 USgal.) should be used for a tank with a maximum content of approx. 360 liters (95 USgal.)

DOC Skimmer 9404 compact
The trend within the nano aquaristics area is continuing. This type of tank is already often being offered with cabinet technology. If the question of the skimmer is addressed, you will find a multitude of models which are often too big, too expensive, or too inefficiently dimensioned. Thanks to the experience we've been able to gain in the field of motorized skimmers since 1963, we were able to develop the successful Comline DOC Skimmer 9004 four years ago. The unit is highly compact with minimum space requirements, and it can operate efficiently in nano aquariums with up to 250 liters (66 USgal.). This model can also be used in cabinet filters with a variable level from 80 to 250 mm (3.1" - 9.8") thanks to the specially designed container 9004.500. It is able to compensate water level fluctuations without the need for a constant adjustment, it contains a durable controllable Comline pump and a post filter just like any DOC Skimmer cabinet. The Comline DOC skimmer 9004 can function optimally in this 9004.500 container just like in any customized aquarium. Therefore, it offers the benefits of our larger models such as the easily removable cup, the Anti Over-foaming System and the Flash Skimming feature. The DOC Skimmer 9404 compact is very easy to install, features silicone feet for a completely silent operation and can be easily positioned in every nano cabinet filter.

Energy Saving


Comline DOC skimmer 9004, very...
efficient, quiet and market-tested.

Acrylic container specifically adapted for...
the 9004, or for every customized device on the market.

Base plate with silicone feet,...
no vibrations will be emitted in the filter.

Comline energy-saving pump 900, energy-efficient...
and adjustable from 250 l/h (66 USgal./h) up to 850 l/h (225 USgal./h).

Removable post filter enables a...
perfect added mechanical filtration down to 300 µm using nylon fibers with only a minor biological action. This ensures that no unwanted nutrient and nitrate deposits can develop in case of longer cleaning intervals. The filter can be filled with other filter media, such as activated carbon or phosphate absorbers.