Tunze DOC Skimmer 9012 DC review

Posté le 5 février 2016 par

After the Tunze Comline Doc Skimmer 9012 DC unboxing made in November, I present a test in my tank of the Tunze Comline Doc Skimmer 9012 DC.

Brief Reminder of product characteristics

The Box and out of the box

The product is in a beautiful box and the product itself is well finished. The look itself is quite nice and sober which is essential for the visible material in the tray.

The Comline DOC Skimmer 9012 DC skimmer is supplied with a Magnet Holder effective up to 15 mm glass thickness. Consumption, adjustable, is between 5 W and 21 W, the bucket volume 0.7 l, the air flow 600 l / h, with the magnet holder dimensions: L 140 x W 110 mm x H 415, the depth immersion about 255 mm to 285 mm.
Compared to the 9012 (constant power pump), for which the maximum air flow is about 400 l / h with a consumption of 11 W, the 9012 DC, can provide 50% more flow at the power setting of the pump at its maximum.

Text context

I installed the Tunze Comline Doc Skimmer 9012 DC in my tank of 120 l instead of a Tunze Comline DOC Skimmer 9005 that worked there for 7 years.

Specifications for the 9005 and its use

Reminders for the Tunze 9005: water: 800 l / h, air: 500 l / h, 12 W. It is a model of ‘first generation’ which had initially no Magnet Holder. I’ve added later.
I use the skimmer 12 hours over 24 hours (in parallel of my lighting). This for reasons of noise at night. The considered noise is the one of the bubbles produced for skimming. Skimming resulting product is generally sufficient for my tank and its people (if I take the rate of NO3 as a criteria, even if it’s simplistic). Twice in 7 years, in the case of specific pollution, I left rotated 24/24. Measuring NO3 with conventional colorimetric tests found 0 mg / l, 99% of the time. I empty and clean the skimmer cup once or twice per week. The amount of foam produced is generally less than one centimeter of liquid in the cup. In addition, the amount of liquid drained into the week, when cleaning is greater in the case of two dumps / cleaning that at one. Another feature of use, the water from Osmolator the arrives into the skimmer (plugged into the socket ‘ozone ‘, there is enough air flowing elsewhere).
Why the choice of model in the range Tunze? The 9004 is a little small and the 9012 seems overkill for my tank. DC 9012 must enable the setting to find a good compromise power via the power setting the pump in addition to the flow of the air supply.

Expected benefits before test

  • Aspiration of surface water. I sometimes have a slight surface film this weekend (between two ferry interviews). This is especially true when leave feedback, this is due to the increased use of food dispenser (flakes & granules). Excluding holidays, I fed once a day sequins most once frozen (brine or mysis). The flakes are the source of the observed light film. At least a decrease is expected..
  • A little more skimming and margin if necessary
  • Slightest or equivalent noise
  • Power consumption less or equivalent if my previous
  • Interview annual ‘easier (inside of the 9005 is not very accessible for thorough cleaning)
  • Low tension. Less I will have 220V equipment directly into the tank, the better it will be!

Into the tank and usages


Fixing the skimmer is made by magnets using the skimmer silentblocs silicones. As reported on the special instructions to that effect, watch your fingers when setting up (I confirm …)!
The magnets are suitable for a 10 mm glass.
Do not take this information lightly
The electric drive can be fixed with a scratch & double face sticker provided.
Without and with magnet holders

Initial setting

I first rinsed the skimmer thoroughly with fresh water and did a test in a bucket of water for ‘grip’ and make sure everything worked properly before putting my tank.

The power of the pump and the amount of bubbles produced are significantly superior to those of 9005 when at full power.

Not wanting to disturb too much my tank by a sudden change, I started with a pump power adjustment to the lowest and opened the air to the maximum. I compared the amount of foam produced with the primary objective of producing about as much in the beginning.

From the first minute I have a bit of white foam that occurs. After a few hours the foam comes continuously near the top of the cup but does not drop even in the bucket. The next day, I have a juice being yellow / green in the bottom of the cup, about 2 mm.

Note: I took out the skimmer 5 mm of the tank after a few minutes to avoid outgoing microbubbles on the surface. I had submerged a little low.
I have a little bit of micro bubbles that come out of the bottom of the skimmer (very light).


The position (height) of the skimmer impacts the skimming and the exhaust of microbubbles in the tank. Ascending it very slightly from the original position, I was able to avoid sending bubbles in the tank. Put the water level in the middle of the grid for the surface water intake (this corresponds approximately to the automatic setting if Osmolator Tunze was plugged into the back).

The adjustment of the amount and the type of foam produced is a combination of adjusting the pump power and adjusting the amount of air.

Other settings

The initial setting for the first week gave me a little less foam (somewhat darker) than 9005. With the 9005 I had 65 to about 100 ml per week, sometimes up to 200 ml when the skimmer was recently cleaned out and I emptied the cup twice a week.
For the 9012 DC, I chose a new setting. I moved the cursor between the first two ‘notches’ (there are 6) electric power of the pump. In this case, the skimmer really produces much more foam. To avoid filling the bucket in minutes / hours, I decreased the air supply with the plastic tap. With this setting, I get a little more foam more easily than my previous skimmer. I adjust to get about 30% more (and darker).

The setting box and its support

The combination of the adjustment of the pump and the air inlet allows a very fine adjustment. You need to experiment to find one that suits you (for the desired compromise: amount / concentration of the foam).

The pump is very powerful. It is night and day comparing to my previous skimmer. There is no doubt that we can skim a much larger and ‘dirty’ tank with no problem. In the latter case, the bucket skimming ‘Holiday’ cup of extraction (optional) may even be necessary because the skimmer can be really powerful for its size.

During some tests and use cases


Before & later


The used space is quite close to my old skimmer. The cup is less wide but above. Overall, this new model is a bit thick ‘of 1 cm with a little more height above the water (approx. 4 cm). The height is similar to the height under water. The cup takes up less space in width; it is the width of the body of the skimmer.

Electric consumption

The aim here is mostly a relative measure between the two devices to ‘give an idea’. The measure is not made with laboratory device; the absolute accuracy is ‘relative’ but precise enough in my opinion.



The aim here is also a relative measure between the two devices to ‘give an idea’. The measure is not made using a laboratory device, but confirms what my ears perceive.


To my ears the noise level, compared, seems close though the noise of air bubbles is different between the two skimmers. I do not perceive noise of the pump in the case of my setting.

By increasing a little pump power, the noise does not increase much. The slight difference is seen especially very close the tank.
I maintained the habit of stopping skimmer 12h each night. The foam is produced very quickly at startup.


Weekly : the cleaning of the bucket do not cause any problem. The bucket has some ‘horizontal stripes’ for the look, a smooth surface could be better for cleaning. A button ‘clean cup’ is available on the remote control to stop the pump without any disconnect. We can turn back on manually or wait 10 minutes with auto power delivery.
Video skimming 4 (Without bucket while cleaning: minimum power pump!)
A brush is provided. It is just fine for the cleaning bucket (although very useful for reaching the bottom).

Annual or more : disassembling in two parts of the skimmer body will allow an easy cleaning (real test in a year J).

Good idea

The skimmer has a slot in the back to put the optical sensor of the Tunze Osmolator. This also allows the water level to be in line with the vertical positioning of the skimmer in the tank. It is a great idea.

For a Tunze 3155 that includes an optical sensor and a mechanical sensor you must still keep the external mounting for the mechanical sensor. Maybe we will see a little support for having the possibility of attaching the sensor with the safety float that can be put on the side (each side as needed) in a future release? I think that it would be a real ‘plus’. It is true that without the first idea Tunze I will not have this second.

Even better: I had liked to have something to fix the osmosis water supply hose directly on the skimmer saw that I bypassed a socket for air into my Tunze 9005 for this for years.

Personal usage for the Osmolator

Suite à l’idée de Tunze d’accoler le capteur optique au corps de l’écumeur, j’ai fais un test en plaçant le magnet ‘externe’ de l’osmolateur dans l’écumeur. Ceci pour libérer de la place ‘visuellement’ sur le fond de mon bac en ayant les deux capteurs de l’osmolateur sur le coté de l’écumeur. L’osmolateur est maintenant sur l’écumeur et non sur la vitre.
Following the idea of Tunze to attach the light sensor to the body of the skimmer, I did a test by placing the external magnet of the Osmolator in the skimmer. This is to make room visually on the backend of my tank by having the two sensors of the Osmolator on the side of the skimmer. The Osmolator is now on the skimmer and not on the glass.

With and without the Osmolator on the backend glass
With Osmolator on the skimmer
With the Omlolator on the skimmer, without cup – internal Magnet Older view

As you can see in the picture ‘in the skimmer’, the magnets may interfere with water circulation. But as the skimmer has a very high flexibility with high-powered pump I thought that this should not really interfere in the end (it foams perfectly as desired anyway). I will see with time.

Balance against the expected benefits

After a few weeks of use, I can confirm that the objectives for the six selected points (Aspiration of surface water, no more noise that the previous one, less electric consumption, easy cleaning, low voltage, margin skimming) are filled.

I like
  • Surface suction device with film removal
  • The space in the tank (not really more than some descents)font]
  • The skimmer is well attached to the tank (discreetly))
  • The low power consumption
  • The adjustment of the electrical power of the low-voltage pump
  • The power full pump
  • The joint setting ‘power pump and air intake’ to ‘select’ the amount and kind of foam
  • Simplified cleaning with the full opening of the skimmer
I do not like
  • Nothing, besides the bubbles at startup (standard on many skimmers).
In an ideal world I would have also liked
  • A support for the two sensors of Osmolator 3155 and attachment for the arrival of water directly on the skimmer.
  • Have the optional bucket ‘holiday’ and its output for connecting a pipe, for the standard (with a removable plug, in the case of we do not use the output). Of course, it is not for tank size like me, but it would be nice especially for larger tanks that may also use this skimmer.


After a few weeks of use, I really like this product. I am keeping it.

Manufacturer information (soon) : Tunze

French version

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