Comline Doc skimmer 9012 DC micro bubbles

[Idech]

Hello,

ever since I did a complete cleaning of my skimmer (4-5 weeks ago) it has been spilling micro bubbles non-stop. It didn’t use to do that for the first 18 months so I don’t know what happened. It’s skimming fine.

Someone on this thread had the same problem (see post #7). They saw a Tunze picture online showing a skimmer with a provided sponge on the bottom. They put a similar sponge on theirs and it fixed the problem.

Tunze 9004 Skimmer Generating Tons of Microbubbles in Display

Hey all. I have a 50g rimless tank with no sump - instead I use an in-tank Tunze protein skimmer and filter. They seem to do the trick, but I do get a ton of microbubbles being kicked out from the skimmer back into the tank - and not just when the water level gets a bit low. I'm not sure this...

www.reef2reef.com

@rvitko mine did not come with a sponge either. Should I just cut a piece of foam and place it on the bottom, like the picture shows? If so, how thick should it be for my skimmer ? And why aren’t these foams provided ?

Thanks !

 

[rvitko]

The sponge is not included and I would hesitate to use it, it is a filter part that can be used where bubbles are a critical issue, 3162.200 for 9004 3168.200 for 9012 but it causes other issues like bubbles backing out the intake when it clogs and it requires regular maintenance. Something is likely assembled wrong, the other possible culprits are change in depth or any additives or other changes, like new filter floss or media, especially organic exchange resins and any floss not specifically made for aquariums and marked "phenol free". On the 9012 a common issue is that while the air intake can go on two ways, only one is correct, the solid side needs to be against the wall and the outlets should be symmetrical.

 

[Idech]

The sponge is not included and I would hesitate to use it, it is a filter part that can be used where bubbles are a critical issue, 3162.200 for 9004 3168.200 for 9012 but it causes other issues like bubbles backing out the intake when it clogs and it requires regular maintenance. Something is likely assembled wrong, the other possible culprits are change in depth or any additives or other changes, like new filter floss or media, especially organic exchange resins and any floss not specifically made for aquariums and marked "phenol free". On the 9012 a common issue is that while the air intake can go on two ways, only one is correct, the solid side needs to be against the wall and the outlets should be symmetrical.

Okay, when I’m up for it I’ll take it apart and show you how I reassembled it, as the other causes don’y seem to fit this case.

Thanks !

 

[Idech]

@rvitko I disassembled and reassembled the skimmer again, today. There is one part that I had put upside down, and I fixed it (the little plastic tube).

I put it back in the tank and it’s still making tons of micro bubbles, this time coming from the right upper side. Before the micro bubbles seemed to be coming from the bottom, so I don’t know if I fixed a problem and created another one. I watch Tunze videos to make sure it’s okay though.
See this short video :


Here‘s how it was when I took it apart :

Part that was upside down (small tube) :

Here is how I reassembled it :

I really want to fix this, it’s ruining my water clarity and it’s driving me nuts.

Thanks for your help !

 

[rvitko]

That spacer is unimportant, it is really just there to restrain the pump in shipping. The impeller cover seems to not be fully attached in the last photo, it should be centered as you show in the earlier photos. This could have some impact. The bubbles are exiting a seam in the body panel, this is not unusual, there are small gaps where the tabs are, this is typically sealed by biofilm within some weeks of use assuming it is not opened. The main thing you can do is get teh skimmer out of the path of flow so the bubbles just rise up and out, for example if you reversed the skimmer and filter placement so that side was against the glass, the bubbles should rise out instead of being picked up and blown around.

 

[Idech]

That spacer is unimportant, it is really just there to restrain the pump in shipping. The impeller cover seems to not be fully attached in the last photo, it should be centered as you show in the earlier photos. This could have some impact. The bubbles are exiting a seam in the body panel, this is not unusual, there are small gaps where the tabs are, this is typically sealed by biofilm within some weeks of use assuming it is not opened. The main thing you can do is get teh skimmer out of the path of flow so the bubbles just rise up and out, for example if you reversed the skimmer and filter placement so that side was against the glass, the bubbles should rise out instead of being picked up and blown around.

It was making bubbles before though, so that can’t be the problem. What else could it be ?

As for the cover, Ddo you mean it’s not turned all the way in ? I did make sure I tightened it.

 

[rvitko]

Actually the cover is on 180 degrees reversed, the solid wall faces the front, look at your first photo prior to disassembly. It is normal to have some bubbles exit where the tabs engage, the key is that there is very little to no flow in the skimmer area and then they just rise up and out, if you can get that side against the glass in a calm area they won;t be blowing around the tank.

 

[Idech]

Ok, thanks.

So just to make sure it needs to be put together exactly like this ?

https://www.reef2reef.com/attachments/1693858244194-jpeg.3311577/

 

[Idech]

I reassembled it again and saw what you meant with the impeller cover. I fixed that and made sure I closed everything well. Then I adjusted height.

It’s still making micro bubbles, this time coming from the bottom, more diffuse. It started doing it after I cleaned it, so I figure by cleaning it I reopened tiny holes in the casing, which are letting bubbles through. Last time it took 3-4 months before stopping (by then it was dirty inside) so I suppose it will do the same.

It’s really annoying and something that Tunze should work on. We work hard on our tanks and having bubbles scrap the view is not very pleasant, to say the least.

 

[Fritz05]

I know this is an older post, but I had issues with microbubbles coming from my 9012DC and after trying many things the only solution was to place a piece of filter sponge in the bottom of the skimmer body. The piece I use covers the front half of the opening and has reduced my bubbles by 90%. Changing the placement of the skimmer and the air volume did absolutely nothing. It is skimming fine.

 

[Idech]

I know this is an older post, but I had issues with microbubbles coming from my 9012DC and after trying many things the only solution was to place a piece of filter sponge in the bottom of the skimmer body. The piece I use covers the front half of the opening and has reduced my bubbles by 90%. Changing the placement of the skimmer and the air volume did absolutely nothing. It is skimming fine.

I never found a way with mine either and using foams was not something I was interested in.

I’m upgrading my tank hopefully next January and I’ll have a sump then. I’m hoping the 9012 will do an okay job in there but if not, it will be replaced.

 

[Midrats]

Was it working properly before you cleaned it? The only times I have every experienced excess bubbles escaping were either improper assembly or some kind of surfactant.

 

[Idech]

Was it working properly before you cleaned it? The only times I have every experienced excess bubbles escaping were either improper assembly or some kind of surfactant.

I thought it wasn’t, so I disassembled it and cleaned it. But honestly I’ve had it for 2 1/2 years almost and during that time, it pretty much always threw microbubbles in the tank. Except maybe for a short period.

I’ve given up unless someone has an easy answer.

 

[Idech]

@rvitko I took it apart again to try and fix the microbubble issue. It’s really bad. Right now it looks a little better but I just put it back in the tank, so we’ll see tomorrow.

Here is what I meant when I said the screw of the impeller looked damage (I know now it’s not a screw, as you said). It feels very solid, no loose parts.

Should it be replaced ?

Here’s how I reassembled the skimmer, at least part of it :

Thanks for your help !

 

[Idech]

Here is what I did to try to fix the microbubbles :

1) the pump was not sitting completely in the groove on one side. I fixed that.

2) there was salt deposit in the air tube so I detached it and ran hot water in it to get rid of it.

Question :
3) The impeller cover. The « Tunze » sign faces opposite of me when holding the cover (meaning it’s facing the back of the skimmer). It’s the only way it would fit. Is that on right ?

 

[reely989]

I hope you find an answer because I’ve yet to figure out how to run the thing without bubbles. I assume I just have too much flow in the tank and it’s picking the bubbles up but I don’t know. Very frustrating to say the least.

 

[Idech]

I hope you find an answer because I’ve yet to figure out how to run the thing without bubbles. I assume I just have too much flow in the tank and it’s picking the bubbles up but I don’t know. Very frustrating to say the least.

I’m upgrading so won’t need it anymore. I’ll have a sump and a big skimmer. I made sure to include a bubble trap in the sump. No more microbubbles !