9020 Skimmer perf

[nakazoru]

I have a Tunze 9020 skimmer running or 1 year now and I must say I'm not quite satisfy with its performance.

I ran it with my 5 ft tank, low bioload. While I believe that it may not be the problem with the skimmer, it may very well the fact that I have problem tuning it for optimal performance.

The way I set up:
1. Skimmer is fully submerge with abt 5cm off the water level mark.
2. The skimmer has circulation flap fully opened.
3. The Air inlet screw is losely opened which causes big bubble rather than fine ones. If I close it further, the bubble level drops to the point where skimmates are not able to overflow out. (Skimate at the neck)

What can I do to improve the performance.

 

[rvitko]

The bubbles should not be large, I suspect the venturi is damaged, broken or clogged. Did it work well in the past and has slowed in performance?

 

[nakazoru]

Hi Roger;

When I means large bubbles, I meant that the bubbles are large even compare to a airstone skimmer about 5 cm in diameter. See attach picture.

It has been the same since I have this skimmer. The bubble level has been inconsistence and bubble large. Hardly able to cope for my 200G tank with only 7 fishes and some corals. Because of that, I hardly dare to stock up.

Hope the picture can give you some idea and you able to help.

 

[rvitko]

That looks correct, it is building a foam head and that is rising up properly. I would probably just open the air adjustment another full turn to get a more watery skimmate.

 

[nakazoru]

Was that right? I was expecting finer bubble. Maybe tunze skimmer is just different with all the earlier skimmer I own.

Thanks anyway.

 

[rvitko]

The bubbles seem to be fine at the bottom but they build into larger foam at the top, this is the way every skimmer I have seen works. It is a venturi skimmer, and the bubbles are larger than a needlewheel skimmer for sure. For example the 9410 skimmer the bubbles are less than 1/3rd the size of the 9010 bubble.

 

[nakazoru]

Ops, that statement is true for a venturi skimmer, most of my skimmer is all needlewheel. Guess that is my confusion.

For 1 year, I;m still not use to tuning just by the air blue knob. So use to adjusting with a combination of inlet/outlet valve and air valve.

 

[nakazoru]

Hi Roger;

Thanks for the feedback.

I have essentially tweak a little, by submerge a little deeper, open the intake flap to fully open. These brings the bubble level higher.

I looked deeper into the internal structure of the skimmer to better understand how it works. I must say it is different from any skimmer I ever own. I was skeptic how this samll skimmer is going to handle 200G, now I'm convinced.

Having understood the fundamental, it produces skimmate/skim bubble to the extend where it will overflow in 3 days, and it stinks.

I will have to figure out a way to burst the bubbles that is in the collection cup.

Very happy now.