micro bubble trouble in my new 90g

[adeian]

Hi everyone, hopefully someone can see something I missed and help me out.

I just finished cycling my new 90g tank and started to move my fish over from their old 30g home. But I've been having a problem with micro bubbles in the return from the sump. It's not constant, they come in bursts and I've tried everything to get rid of them but nothing is helping.

The connection to the pump is under water, the sump has a bubble trap and I can't see any bubbles in the return line. At the head the PVC connection is under water so the air leak isn't in any of those places.

The return has a hole in the 'elbow' of the 90 degree to break the siphon and it's got water coming out in a nice steady stream. I screwed the adjustable nozzels tightly and used thread tape to seal the connection inside and out. I've also use the tape to cover the first two joints in the nozzels to try and keep out air but I still get it. Nothing I've done has even decreased the amount of bubbles. Instead it's worse now if anything.

Here are some pictures. Can anyone spot something I did wrong or maybe missed?

 

[cooltop]

What about where it connects under the tank ? I have the same setup on my 72 the only difference is it was post to have a hole in the elbow but it didn't and I never worried with it

 

[cooltop]

Also turn your protein skimmer off for a whole and see if they go away

 

[adeian]

The connection under the tank seems air tight. The hose is all the way over the barbs and then clamped. I'll try sealing that up some more though as well as turning off the skimmer. I'm not seeing any bubbles in the sump at all though.

 

[adeian]

Nope didn't make a difference.

 

[cooltop]

Post a pic of of the sump and the return

 

[Sarcothelia]

Turn off skimmer or whatever else you can turn off to see what the problem is. Just turn them off one at a time so you can cancel things out.