Here’s a brain puzzler. Last night, I turned the pump off for 8 hours (thanks Marty - good tip) to see if could get any settling (this was before realizing there was algae in light). Turned the pump back on in morning and did the light cleaning as described above.
This afternoon, noticed my resting psi was 3-4 psi lower than it had been since opening 14 days ago. Even the last few days when adding DE, and frequent backwashing, right after the backwash it would rest at 17 psi. Now at 12-13. Return flows in the pool look good.
I tapped gauge and gauge has been good last 14 days.
Any explanation?