With the advent of cooler weather, hail storms and El Nino rains, my CYA has dropped from 50 to 40 and now to 30 (rounded up to the nearest 10ppm) over the last three months. During the last two months, daily chlorine loss ranges from 0 to 1ppm depending on windfall debris and airborne particulates (not to forget bird droppings) which are skimmed/vacuumed frequently. Gratefully, the 41F water continues to be sparkling and clear with minor CC levels if any.
CC </= .5
CYA 26-28 (rounded up to 30)
Should I address the descending CYA with a leftover 3" - 8 oz. trichlor puck via the automatic feeder after the FC gets closer to 4 or maybe even 3ppm?
I ask because PoolMath states 7 oz. of trichlor will "raise the FC by 9.6, CYA by 5.8, and lower pH .51" which concerns me because I don't want a return of metal staining due to a sudden push of chlorine/pH levels despite maintaining an appropriate HEDP sequestrant level.
As always, thanks for your help and wishing everyone a Merry Christmas and prosperous New Year!