I registered with TFP back in May, posted a question, got LOTS of good responses . . . .and when I went to update things yesterday, I found I couldn't log in. (Don't know what happened --- even checked my old emails for the authentication email, but could find nothing from TFP. Weird.) Anyway, I've re-registered.
I live in rural Brazil, where test kits for anything beyond basic chlorine and pH are non-existent. In May, my pool suddenly (literally overnight) went from deep blue to green. I added a lot more chlorine which simply disappeared as fast as I could add it. The folks who responded to my posting suggested high CYA (because I'd been using stabilized chlorine for years) --- and, of course, suggested that I get a real test kit.
I just returned from the US with a new TF-100 under my arm, confirmed the high CYA diagnosis, and had to refill about 75% of the pool to get down to a level of 70. I shocked (with unstabilized granular chlorine --- the bleach here is 1%, if that) per the Pool Calculator suggestions, and seem to be back in business with a nice medium blue.
I'm posting a few question about readings on the appropriate forum today, but I just wanted to recount this here in hopes that some of the great members who responded to my original post will happen to read this and accept my thanks!
Frank -- in Bahia
[65,000 ltrs; inground tile; very sunny; no organics; few swimmers; un-stabilized granular; Jacuzzi pump & filter; homemade PVC heater]