Mag drive question
I've had a mag drive 1200 as a return pump in my sump for about three years now. I've noticed that I'm starting to get bubbles in the "U tube" between the prefilter outside of the tank and intake box inside the tank more frequently (I have a trickle filter). I keep on having to lower the intake box inside the tank to increase the amount of water going into the sump but the water level in the tank is noticably lower. I've cleaned the mag drive, filter sponges and as much of the tubing as posible. Is this a sign my pump is starting to ware out or are there other tips I can do to keep the bubbles out of the "U tube"?