210 AGA Double Oveflow Microbubbles

[nadking]

I have a 210 gallon AGA with the double overflows, I bought it used and have recently filled it up and am beginning cycling it. I just put on a couple of florescents for lights and I am seeing alot of microbubbles coming out of the return that arent visible without lighting. Does anyone have any ideas what could be causing this.

[GlassReef]

First of all:

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Do you have a decent bubble trap in your sump? Shine a light into your sump - if there are bubbles in the return side, you need to eliminate them. Are you very sure that your return pump is no pulling minute quantities of air through a tiny leak on the input side of the pump? Is the output of the return line to your tank far enough below the surface that no air can be drawn into the flow?

[nadking]

The pump is submerged, and I do see a few bubbles underneath the bioballs in my wet dry when the trickle meets the water line. However on the open side of the wet dry I do not see the bubbles. I am guessing the problem lies between my return pump and where the water is returned to the display tank.

[Cove Beach]

You could also have a pinhole in your return plumbing that is acting like a venturi and sucking air in. Take a syringe of RO water and drip it on any plumbing joints and see if the bubbles stop. When they do you have the leak pin pointed.