I bought a new home with a 16x32 IG pool. Closed it last fall with phone help from previous owner. Opened O.K. & initial pool store tests consistently showed low CH (130), hi CYA (100), lo TA (70), & hi Pho (300). Water was crystal clear up to fathers day when it had it's 1st heavy use of the year. Next morning pump pressure went from it's normal of 17 psi to 25psi with lo flow from jets & cloudy water.
Backflush of sand filter provided a little temporary relief, but soon back to 25psi. If I put multiport to "circulate" bypassing the pump. pressure & flow return to normal.
Discovered this site & yesterday performed deep clean of filter which had 2" of scum (a lot of cotton wood) on top. Now pressure is back to 16 - 17psi & flow is strong.
Here are my latest test results, taken yesterday before deep clean of filter.
FC - 0
TC - 0
CH - 140
CYA - 99
TA - 90
PH - 7.4
PHo - 300
I read here that using tabs in auto chlorinator raises CYA.
What should I do next?