Hi, I have a 36” Hayward ProGrid DE filter. When I opened the pool this year it was INCREDIBLY green and full of algae. However, even after backwashing properly and thoroughly cleaning the grids, the pressure immediately jumps to 25 PSI, before I can even get to the skimmer to add DE.
Some things to note:
1) There are some but not a ton of air bubbles coming back into the pool while on filter
2) Opening the top air valve on the filter doesn’t relieve any pressure
3) The jet pressure is incredible while on “recirculate”
4) All gaskets before the pump are in good shape and in proper position.
5) The pool’s water level is a little high, certainly not too low
I have absolutely no clue what else to look at. Any ideas?