Hi all. Well, I just opened my pool for the season to a moderate green, I brought the FC up to 22 and ran the filter 24/7 and the next day it was nicely cleared. I tested at sunset and got 22 FC 1 CC and again at sunrise and got 22/.5 so I figured the shock process was complete and I could let my FC level drop to normal over the next couple of days. I forgot that my CYA was low at closing last season, and I had to add a fair amount of water over the winter. I tested tonight to see how things were doing and was surprised to see FC 2.5 CC 0. I'll run a full battery of tests tomorrow but obviously my CYA is very low.
My question is, how much chlorine will burn of by the sun with little to no CYA? Hypothetically, if my FC level was 50 could it burn off in one day of strong sun? Or is there a maximum that would burn off during the day?
On a side note my bleach supplier (walmart) has repackaged their bleach to an 8.25% concentration 121 oz bottle. The pool calculator doesn't list that size for the calculation of how much to add/what level increase you get. Is the formula available or has anyone done a conversion.