I have in in-ground pool that i am having some difficulty with. I suspect there might be a hole in the return lines. The pool is set up like follows: 2 skimmers on one line into filter. 2 return lines come out of filter one to step returns and one to main returns. I just backwashed the filter (DE) and the pressure has come down to the normal 12 psi when I have the main returns on BUT the pressure is up at 20psi when I turn the step returns on. I need to use the step returns as there is a hole in the main return lines. Why would the pressure be so hi on the step returns?
Would a clog in the return line cause hight perssure in the filter?
Please help. My kids want to go it.