Bubbles in return

[pseudorand]

My return pump spews out bubbles after my last few water changes. I imagine there's an air bubble in the overflow return. Any way to get rid of it without taking the pipes apart or just waiting?

It also didn't used to do that. What am I doing wrong in my water change to get a bubble stuck?

 

[laverda]

Is your return pump external? If check the intake to it is not restricted. If the intake is undersized or restricted, external pumps will suck air past the seals. The seals are designed to keep water in, not air out.