Sure wish I had found this forum earlier!!!
We followed the advice of a "friend" and semi-closed the pool in December. (N FL) We covered it and ran the SWG & pump several hours a day. Water temps were about 50. I did not test the water while covered upon said friend's advice.
Last weekend I took the cover off. Water was clear, looked great.....then I noticed the build up on the plaster. It is a white, hard deposit in large patches & feels very rough. (this is a new pool put in last June. Super smooth when we closed it).
Here are my numbers at opening: pH 8.0+
CH 570 (CH fill water is 200)
Water Temp 67
I dropped the pH to 7.0 -7.2 & Cl up to about 2.0 and have been brushing like crazy. TA is down to 60 with the lower pH. I can scrape the build up off with my fingernail but the brush isn't really getting it.
Is what I'm doing going to work or do I need to add something/ do something else? I have fought rising pH and high CH since we started but I attributed that to the pool curing.
Another weird thing, I pulled the salt cell to check and clean and it was in good shape!