I've got a 48 sq. ft DE Filter on a 13000 gal pool. If I completely break down the filter and add new DE I usually get a starting pressure of 8 psi. The problem is that the pressure can rise all the way to 30 psi in about 3 days if I leave the filter. Now I admit that I don't have the cleanest pool on the block but it is no swamp either.
I notice that if I shut off the pool pump when the pressure is high for say an hour and then turn it back on the pressure will start off at a normal psi and then fairly quickly rise to a higher one.
My question is: How long should a round of new DE last? 2 days , 2 weeks 2 months?