Slowly losing pressure

When pool starts, pressure strong but over the course of a few hours it drops to almost nothing.  There are no air bubbles in the pump lid and it never loses its prime.  If I turn it off and turn it back on, the pressure jumps back up.  If I turn it up and open the air valve, it releases a little it of pressure.  It will prime back up and start with full pressure.

Filters were fine but out of an abundance of caution I replaced them with brand new filters which did nothing to help.  Any ideas??

Hi Glen, is there a noticeable difference in the flow of water going to the pool as the pressure drops, and what is the reading on the pressure gauge as this happens?  Algae, even if you can’t see it, can cause strange things like this to happen.  I would recommend checking your sanitizer levels after the sun goes down and again before it rises.  Any change indicates an issue with algae, so follow these instructions to maintain a shock level of chlorine and maintain it until everything recovers.

Test strips don’t give an accurate reading, so use something like this Taylor K-2006 test kit with FAS-DPD tests for chlorine or the TF-100 Test kit.  Get the Smart Stir and you will feel like a junior chemist!

Pool is under an oak tree and it turns out one of the valves was packed with leaves!  The valve would sort of clear when the pool was turned off but then leaves would be sucked back in.  Once they were cleared, everything was good.

I’m glad you found the issue and that it was relatively easy to fix.  Enjoy your backyard oasis!