Installed the pool in August two years ago (long story but did it myself, big learning experience)
FC - maintained between 3-5
PH - ~7.5 (had a lot of trouble holding it)
TA - very low
CH - very low
CYA - 35
Close the pool the first year with a "pool closing kit" - Opened up to a green swamp, no CYA
After cleaning it up, I raised the TA to ~80 with baking soda and the CH was corrected using calcium shock.
Raised the CYA to 45 this time as my sun loss seemed to be high.
No more PH instability after adjusting TA with the baking soda.
Pool was sparkling with several comments asking how I did it and one 'who's your pool guy?'
Closed it late (water temp ~50Â°) with only 12.5% bleach at FC = 12.
This spring I opened the pool to clear water (except what junk fell in from taking off the cover) with a FC = 2.
I had run out of reagents to test CYA so just assumed that with no algea bloom I would be fine
Just tested last night with my nice new TF-100 kit to find no CYA - perfectly clear after mixing for a minute.
PH is stable at 7.5
FC was 3 by both OTO and drop testing
CC - zero
Where does my CYA go? I do drain 3"-4" several times during the season from rain but definately not enough to zero out the CYA.
Other than using the closing kit the first year, the pool has never seen anything other than 12.5% bleach, baking soda, and PH +/- adjusters (only before getting TA correct).
Is there something else I should be doing to combat this CYA loss?