I've been a pool owner for 9 years now and usually can solve issues with logic...This one has me stumped !

When I opened my pool this year (Memorial Day), I would turn on the pump and everything would run fine for around 15 minutes. At that time, no further circulation was evident. The PSI in the filter stayed the same but their was little to no suction in the skimmer or the return lines. After listening to others (not on poolforum.com), I figured the time was needed to change my valve and filter. So, I spent the money and bought a new Hayward Pro-Grid DE Filter and 6 position valve. I redid all the plumbing and wallah...no leaks... I thought I was now going to enjoy another season of swimming.

No such luck. After 15-30 minutes, the same thing is occurring except the PSI in my Filter rises ~10 PSI.

I'm not losing water so I don't think there are any leaks to the piping underground but I'm at a loss.

Any ideas would be greatly appreciated !!!!