powerhead

I have a question about powerheads on a 55 g Hap tank I'm debating on the Aquaclear 70 I like it due to I can add a quick filter to polish the water thing I don't like is I'm told the suction cups let it rattle and they fall. There is the MaxiJet that can be used with the Sure Grip magnetic...

For a 150 gallon. We're using a MaxiJet 1200 with a vinturi. The wood shrimp like it and it helps ensure surface movement if filters get clogged, etc. I got it 2nd hand and it seems to be dying. It may just need a new impeller, but I figured I'd check and see what people like. I do like...

The stupid thing is spitting out little bubbles... what's up with it and will it hurt the fish?