Microbubble Issue

[Chibils]

My return pump (Mag 9.5 on a 90G) gives off tons of microbubbles between my sump and my DT. The compartment that the pump is in has no microbubbles; there's a bubble trap on the incoming/skimmer chamber and the water in the fuge is clear. The pump is fully submerged, so I know it's not taking in any air. They just magically appear out the spout of the loc-line.

[heyfredyourhat]

Has it been running for a long time?? I noticed that when i first started using my eheim 1262 it was a bubble machine, but after a few weeks there is nothing. It is actually quite amazing how much more clear my tank is now with out those pesky bubbles!

[Chibils]

It's been running for about a month. It gets much worse when I top off, which I find odd, as I'm raising the water level.

[heyfredyourhat]

Is the pump sucking air from somewhere?? I am not familiar with the mag pumps, is it submerged?? I know with my eheim being submerged it would create a vortex and shoot tons of bubbles, so i just raised the water level in the sump and voila.

If it external then maybe it is just sucking in air from somewhere, or when you top off that creates some sort of turbulance and teh pump will suck air...Not sure...