CYA going missing


Active member
Mar 3, 2015
We've had a lot of rain in the Houston area lately and my pool has stayed pretty much balanced. But my CYA seems to be very susceptible to being lost. We've had slightly under 5 inches of rain this week, and I'm guessing I only lost 3 inches or so of water (based on pool levels and normal evaporation rare) but my CYA is back down at the 50-55 level as of yesterday yet on the previous Sunday it was 70. All the other levels have barely been affected.

This is not the first time this has happened this year (ok so it is my first year with a pool) so what is going on? I'm getting fed up of always adding CYA, it's almost enough to make me turn down the salt cell and start putting pucks in the skimmer to keep topping up the CYA whilst we keep having all this rain.

Anyone know how much CYA is in 3" pucks? I've got a bucket left over from before the pool went over to salt.

Yesterdays test results (TF100)
TC - 4(ish)
FC - 4.5
CC - 0
pH - 7.5
CH - 400
TA - 60
CYA - 50-55
Salt - 2800
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