I couldn't figure out why I was using so much liquid chlorine (put in 2 jugs of 2 1/2 gallon 10 percent before I went out of town for 2 days) until I tested my CYA (which was around 50) and now it is 0. FC was also 0 but that's no surprise with fun sun, 90 degree temperatures, and 0 CYA.
Is there something out there that eats CYA? I have not had this problem in the past and searching the forum I couldn't find anything similar. I have not backwashed that much. Instead I have had to add water due to evaporation (I don't think it is ever going to rain again at my house) and a leak we had to fix.
I'm off to buy more CYA and chlorine. I'd appreciate any thoughts! Thanks!