New pool. 23k gallons with attached, raised spa with spillway. Pentair VS 3hp pump. 2 skimmers. piping is a mix of 2.25" and 2.5". I'll have to verify at the pad tomorrow. The returns nearest to the pad are about 60 ft away. Roughly 90ft for the spa. 8 jets in the spa. 5 returns plus 1 for the polaris 280 in the pool. It is a pentair cartridge system.
What I am seeing is a loss of flow after 2-3 days. I thought at first that it was only happening when running low rpm's. The past few days I've only done cycles of 2500rpm and 3100rpm. I could feel the problem when running lower rpm's just by sticking my hand in front of the jet on the tanning ledge. There was almost nothing coming out. I'm just judging by the spillover reduction at higher rpm's. It reduces to slow drips after a couple of days. Filter psi is 18.5 at 2500rpm. The jandy valve is clocked to send some return to the spa in pool mode. I've experimented with it quite a bit. Swapping to spillover mode at 3k rpm where the spa gets all the pressure and no suction still flows a ton of water.
What seems to reset it all back to normal flow is venting the system a while. I thought that might mean a loss of suction, but I see that my pump stays primed overnight. The pump is elevated above the pool.
Thanks in advance for any help.