HELP New Tank and sump = Microbubbles


New member
I have a 65 gal AGA with built in overflow, I have a 20 gal long for my sump and its going crazy with microbubbles.... Here is how my set up is..
1 1/4" stockman stand pipe
3/4" return line being fed by a quiet one 5000 pump inside the sump
turbo flotor 1000 in sump skimmer which is brand new
Return lines in the tank are 3/4" piping with loc line fitings on each end (set up in a tee shape) each loc line is in opposite corners for flow.

My problem is this, the overflow is putting out tons of bubbles in the sump, at first I had the drain above the water level and thought that this was the cause, but I have since extended below the water line and its just as bad but only more quiet.
THe skimmer is putting out tons of microbubbles also, they are dumping into the sump as well thru the return lines or overflow lines at the top of the skimmer....
My sump has 3 baffles whichI hoped would catch most of the bubbles but it is not 100% effective, maybe 60%. So the return pump is picking up the microbubbles and send them into the display tank...

How do I correct this? there are so many bubbles in the display tank I cant see clearly.... when i turn it off it clears up beautifully....

Someone please help me here this is my first attempt to set up a tank with a sump.


New member
how far apart are your baffles? i have read that if they are like one inch apart, it can cause the water to move too fast through them and not give enough time for the bubbles to dissapate


Premium Member
Often microbubbles are a symptom of a new tank. Let it run for a few days to see if it resolves itself.

If not,you probably have one of two issues.

1) Flow through the sump is too fast,

2) There's an air leak in your return line and it's sucking air. It can be so tiny you may never find it but it's sucking air just like the venturi on a skimmer.


New member
Try putting a sponge filter near the return to act as a bubble trap. Since your tank is new this happens sometimes. Send a picture of your sump set up so I can get a better idea of whats going on.


New member
My baffles are 1" apart, unless I am wrong it seems like most people set them that far apart, do you think they are too close together?
The flow thru my sump is the max capacities that the bulkhead fittings will allow which is I think around 600GPM/GPH not sure which one it is.
I will take pictures this evening when I get off of work, hopefully that will help you to help me...

I checked my return line and everything is tight, it is rigid plumbing with the only break in it being a union, the union is as tight as i can get it.
The drain side of my plumbing is where 95% of the bubbles are coming from in the sump, even below water the drain is producing mass amounts of bubbles. With the stockman stand pipe being 1 1/4" in dia then reducing to 1" at the bulkhead fitting, then back to 1 1/4" to the sump, could this somehow be the cause?


Premium Member
If it's running 600gph on a 65 gallon tank it's definitely about twice as fast as you want. This is likely most of your issue. Shoot for 3-5x the size of your display tank for flow through your sump.