Tunze doc 9026 skimmer... Please help!

[RobbieMVFC]

Hi all ......Please help.
I am just about to concede defeat on this skimmer .
I have had it on and off my system for about 8 months and I can never get it running correctly.
At best I will get it foaming for a day and then it will drop down to doing nothing again .
At best it will leave skimat on the inside of the neck of the cup.
I have contacted Tunze via email and I have shown them my set up only for them to say "œohh your doing everything right ..."
I took it back to my LFS and "œhe got it running" mind you it was in a tank full of live rock .I assume that the load was huge and a coke bottle with a air pump would of got skimat out of that.
I have tried various water depths low and high it does not matter. At the moment I have almost drowned the thing. its a the top of the silencer with only the screw above the water line.
Still NOTHING!!!

I also purchased a cheap aqua excl skimmer that pulls out skimat no problems . My issue is I have paid big dollars for this skimmer . I would like to have it running.
After every change/ajustment I make I wait a week
Anyone have any ideas ?
BTW , I have given it vinegar baths .
:sad1:

 

[RobbieMVFC]

also my Bio load is
In my tank I have (3x2x2)

2 wrasse
1 Yellow tang
1 Lawnmower Blenny
2 clowns
1 Chromis
1 Damsel
1 CBS
2 peppermint shrimps
BTA

Torch coral
Toadstool
Tree
GSP
Morphs x10
Alveopora
Brain coral
Candy cane
Zoo’s rock

 

[RobbieMVFC]

The water line is where the blue line is , The red line is where Tunze say it should be,
I have also added a few tank shots so you get the idea of load on the tank

 

[mayjong]

so why don't you put the water line where tunze says it should be?
put something under it to raise it up?

 

[rvitko]

I used a 230/3 for years on a home aquarium, the 9211 is the current equivalent. These skimmers are very finicky regarding water level. It must be constant and it should be absolutely within the recommended range and my experience is it is best near the middle of the range, too high can lead to water drawn into the silencer. I see no need to wait a week between adjustments, but at least 12 hours and the key is very small adjustments, open the air 1/4-1/2 turn and wait if no skimmate or very thick, close it if very watery.

 

[RobbieMVFC]

I used a 230/3 for years on a home aquarium, the 9211 is the current equivalent. These skimmers are very finicky regarding water level. It must be constant and it should be absolutely within the recommended range and my experience is it is best near the middle of the range, too high can lead to water drawn into the silencer. I see no need to wait a week between adjustments, but at least 12 hours and the key is very small adjustments, open the air 1/4-1/2 turn and wait if no skimmate or very thick, close it if very watery.

Finicky is a understatement. I tried for months hovering in between the recommend water levels. This had the same result.
As you can see in the photo its still foaming well enough despite its depth.
Should I save up for a new skimmer ?

 

[rvitko]

Keep the depth constant and give it time.

 

[RobbieMVFC]

Keep the depth constant and give it time.

Roger , Last night I pulled the skimmer out again and gave it a good clean again . I have put it back in the sump with a depth of 70mm (recommended 60-90mm) in the instructions it states to plug it in and adjust the air flow till its half way up the cup .
The catch is that it only ever skims at a depth of about 10mm higher than the water line despite where the air line is adjusted.
Could it be the pump thats the issue ?

 

[rvitko]

It is possible it is the pump, but this is generally a dramatic issue and not something subtle where it would work for your dealer but not you. It just wouldn't work at all. The most common (still fairly rare) pump issue for a 9206 pump would be one that spins backwards and they have so little flow when spinning backwards it is fairly obvious from the few bubbles.

I would disregard that, it takes much longer for the bubble to start to rise in general. I would instead open the air screw 3 full turns, wait a day, open in 1/4 turn increments every 12 hours until you see skimmate collecting, if watery skimmate is collected, do the opposite.

 

[RobbieMVFC]

Hi Roger , I just wanted to express my gratitude.
I got it working although I am not sure what I did .
2 things I did differently is dismantle the black bottom bit of the skimmer .
According to the instructions its is(was) sealed with silicon that if removed would have no effect to the skimmer performance but could produce micro bubbles into the aquarium for a short period of time.
I built up the courage to remove it and clean that part for the first time.
I also removed the hanging brackets and placed the skimmer onto a plastic container.
The skimmer depth as previously stated is 70mm.
I noticed last week when I put it back in it looked to be producing more micro bubbles and the turbulence had decreased.
this provided a more stable layer of micro bubbles .
As of Sunday night it started skimming.
Also there is a sweet spot that air line must be set to. once set it must be left alone for 12-24 hours if your a quarter turn either side you wont get it to foam .
Thanks again for your support.

 

[rvitko]

No problem, I am glad you got it sorted out.

It is possible if debris was built up in the centrifuge that disassembly would solve that. It is not that hard to reseal it with some silicon if bubbles become an issue.

The air adjustment is the most likely culprit, as you said, their is a sweet spot, it is possible to have such violent bubbling that the foam is sheered apart and cannot build and it does generally take 12-24 hours to see the result of an adjustment.