water level keeps going down

[malmanza]

We just bought a house and opened our pool but each time we turn on the pump and we set the valve to filter, circulation, or backwash we lose water. We only lose water when the pump is on. I don't know if I should call a professional.

[mikethepoolguy]

If you have a multi-position vale on your filter it could be the spider gasket inside of it. A way to check it is to put the valve in the filter mode and turn the pump on, then remove the sight glass and see if any water comes out. If water comes out then the gasket needs to be replaced. If water does not come out then you may a more serious problem and a professional should be consulted...