I have had issues with my small in ground pool with a Hayward sand filter for years and finally got it to where I think it will function. The pool was not covered this last year and was loaded with leaves and was black. I have been running the pump non stop for a few days and throwing in a couple bags of shock here and there. Most of the leaves are out, but some are still in. I have to wait until they settle to get them out. My issue is that I have a normal pressure of 12psi and it will go to 20psi after a period of time (Sometimes 15 minutes, sometimes 2 hours). Backwashing and rinsing fixes this for a while, but it soon returns. My question is, does this seem normal for being such a dirty pool? The sand was replaced last year and it seems to run awesome when at 12psi. Once it goes to 20psi it barely is pumping anything. Thanks for any help!