Over the winter my pool ended up leaking (we had a bad winter, and it froze deep enough to pull the plug out of my return). I ended up having to add much more water than I had to in previous years. Amyway, my CYA is now below 30. My pool is now burning through belach like it's going out of style. In the past, I would loose about 1 PPM per day, now its in the 3 to 4 range, clearly I need to boost my CYA a bit (Normal levels are about 40). For the record, the pool is otherwise fine. Passed OCLT (a number of times), clear water, etc. (we will ignore the mice that were living in my solar cover for now).
My question is, I have some sodium dichloro-s-triazinetrione dihydrate granuales already. 99% active ingredients, 56% available chlorine. I would rather use this than buying some stabilizer, but I can't figure out how much to add. The chemical calculator is based on stabilizer, not stabilized chlorine granuales. In the past, if my CYA got a bit low (because of a lot of rain) I would just throw some pucks in a floater, and after a few days it would bring the levels up. I think this needs more than a few pucks.
Anybody know how much to use ?
EDIT: I found it. It is in pool math, but not where I thought it was. For my pool (27,000 gal) 4oz of Di-chlor will result in FC + 1.0 and CYA + 0.9
So maybe 8 oz a day for 5 days or so, and then retest CYA and see where it is at.
Temp: 63 F (Brrrrr)
FC 7.5 (a touch high, but it needs to be that high so it can be OK by evening)
CYA A little cloudy when the tube is filled to the top.