I have a 60 cu ft de filter with a challenger 2hp pump. I have replaced the grids in my filter, replaced the mechanical seal, orings and gaskets in the pump, and have rebuilt the Multi port valve.

I backwash and recharge the filter, pressure is at 10 psi and water is circulating well. After about 1 hr the pressure is up to 20 psi and the water is not circulating and seems to be churning inside the pump basket.

I appreciate any words of advise or recommendations of any possible fixes.