Today I saw that there was no water coming over the spillover from the spa into the pool, so I went ahead and cleaned the Jandy 340 cartridge filters for good measure. That did not help any. So I switched over to spa mode and that works just fine. There is plenty of PSI when in spa mode.
When in pool mode there is no pressure on the filter PSI gauge, but there is plenty of pressure when in spa mode.
The pump primes and operates as normal in both modes, so I am not sure why the PSI drops to zero when in pool mode. I would expect to see no pressure regardless of which mode I am operating in.
I suppose there could be some sort of clog, but it would have to get past the basket filter before the cartridge filter and then past the cartridge filters.
All my pool specs are in my sig, but please let me know what other info I can provide that would help.