I opened my pool a few weeks ago and noticed pressure was high (low 20's) and everything was working except for the deeper end return jet (I have 4 returns, 2 in stairs, 1 shallow end and one in deeper end). For some reason it doesn't work when I start up the pool. If I divert water to it, it begins to work and stays that way for the rest of the day.
The other day I came home and no pressure in the skimmer with the basket floating in the skimmer. I shut everything down and cleaned the filter cartridges. Once everything was turned on the PSI continued to read 25 and skimmer suction was still not normal! My local pool store recommended I use a shop vac to blow the skimmer line from the pump in case there was a blockage. I did that and skimmer suction seems better now but PSI is still 25!
When the solar kicks in the pressure drops to normal (about 12PSI) and when the solar kicks out PSI goes back up to 25!
Any ideas as to what is going on?