Sand Everywhere

Thanks for all the help!!!!

 

Update: I turned off the main pump and all the PH's and the tank is clean. No sand floating around. I turned on the PH's and still nothing......as soon as I turn on the main pump, sand everywhere. The funny thing is.....the PH's move a ton more water than the pump...........ideas please.

 

Aim your returns to the surface to increase gas-exchange. If that doesn't fix it, throttle back the returns with a ball valve (on the OUT side of the pump and not on the IN side of the pump).