Originally Posted by Hholly
Mine isn't loud at all. Did you prime it?
Yep, primed and started it up. Also made sure the water level was high enough to try to minimize the "waterfall" type noise. The bio wheels almost look to be out of round. It's like they are sporadically dumping more or less water as they spin. That seems to be what is making the water noise more pronounced. My 150 is nowhere near as loud as this thing. It's actually almost silent.