120 Gallon Progress

[TheReefGeek]

A mag 18 on a 25g sump is asking for micro bubble problems.

It could be the skimmer, or it could just be the water falling into the sump from the drain line is creating microbubbles. That is what happened to me when I ran too big of a pump on too small of a sump.

I would cut back the return pump, and install baffles.

Better yet, use the mag18 on a closed loop and use a smaller pump for the sump return. Or use a much bigger sump.