Tunze Doc 9004 intense microbubbles after 2 months.

[Moeshi]

My Tunze doc skimmer has been up and running for a little over two months.
I have tried all possible settings for over a week for every attempt.

No matter how I tune the height, air intake or flow placement in the tank, large amounts of micro bubbles still gushes from the sides and underneath the skimmer.

I have tried taking the skimmer apart and clean the various parts, and assemble it according to the manual that came with the skimmer.

If I open up the valve completely the bubbles are greatly reduced, but this causes the cup to fill within hours.
If I close the valve really tight, the tank becomes so filled with bubbles, that the water almost appears cloudy.

The skimmer pulls incredible skimmate for it's size and I'm very please with the product in that regard.

I can't help but feel that I'm doing something terribly wrong.

 

[rvitko]

One possibility would be a surfactant additive was used, any stress coat, dechlorinator, some filter medias which contain phenols and other substances, many vitamins, amino acids and medications will cause this reaction.

Another possibility is the pump is not correctly installed.

The pump could also be missing this plate, it may have come off and be loose in the skimmer, the plate that says TUNZE plugs in under the pump.

 

[Moeshi]

I'm terribly sorry for my late reply. We experienced an immense tragedy in our family, which I wont elaborate.

From what I can see the skimmer looks just like it's supposed to, when I open it up. I have attached some pictures in case something looks really off.
I've had the skimmer turned off the last week, because the micro-bubbles started to gather on the underside of my montipora. I turned it on today just to do a test, and everything is still as described in the OP.

 

[rvitko]

I hope that things are now better and I am sorry for your hardship.

In the first photo the bottom grate is in the wrong slot, it should go in the slot above that. The bottom tail of the plate with the pump rests on that plate.

 

[Moeshi]

I recall the grid being there, but I must have left it in the lower slot after a recent cleaning attempt. I've been using a sponge underneath the pump (suggested in another thread I read), hence why I lowered the grid in the first place. Sadly the sponge didn't stop the bubbles for more than an hour, before it was saturated with air.

Adjusting the grid by itself doesn't seem to have any impact at all.

 

[rvitko]

In general if the air is closed more bubbles escape because the pump pumps more water so the bubbles are traveling much further on a stronger current. It may have been a water chemistry issue that has subsided, I would reinstall it, adjusting depth first so the minimum 22.5cm is submerged and try with the air closed as little as possible. Mechanically everything I see looks correct except that bottom grid.

 

[Moeshi]

Fully opening the valve does indeed help a lot on the bubbles escaping from the bottom, but then instead the cup fills up in 10 minutes. Also a lot of bubbles escapes from both sides of the skimmer, regardless of air intake.

 

[rvitko]

Bubbles from the side will mean the front and back half are not fully closed, some part is in the way, make sure the top plate and bottom plate are fully seated and the intermediate plate (with pump) is in so the very tip of the bottom touches the bottom plate with the holes in it. Looking again at the photos, I see a whit spot near the end of the airline, are you sure the airline is unobstructed and the hole in the cover over the impeller that the air hose is attached to is clear of any salt creep? Basically if this was plugged it would be like the air was already partially closed.

 

[Moeshi]

The white spot is a damage in the tubing (regular rubber stretch mark), and despite countless times of reassembling, air still gushes from the sides. I don't know how I should assemble it tighter than the small 'locks' allow. I will try one more time and report back in a moment.



A thorough reassemble as you described seems to have done wonders for the leaking-issue. Only a tiny, tiny stream of bubbles can be seen coming from the side now.
Sadly the main problem isn't fixed: With the valve fully open the cup fills in minutes. With the valve somewhat closed, the tank becomes so clouded with bubbles that it almost looks milky from a distance. Fish and mobile inverts seem unaffected and so does my softies. My sps loathes the bubbles however and have all begun to close up.

I was thinking about a possible reactant as you mentioned, but I don't run any sorts of additives what-so-ever. The only things to go into the tank is food and ro/di water.

 

[rvitko]

Look very closely at the seams on the side when it is reassembled, any gaps or unevenness points to something being in the way, it is possible to have the top plate under the cup and the screen plate at the bottom in so they are not fully in, just a couple mm extra sticking out and the body doesn't close all the way.

 

[Moeshi]

I don't know what I did, but something went right, and the skimmer is now what appears to be completely sealed from top to bottom along the sides. Bubbles in the display seems to be the same. So far so good!