My CYA is not detectable. I have a sock hanging with 3 c. of cya. PoolMath said to add 28 oz. My FC is 2/4. I added 2 cups of 10% chlorine (before I did the PoolMath). PoolMath said to add 11 oz.
My question is, if I need to add 28 oz of cya, and it's in a sock dissolving very slowly, do I need...