CYA of 30-35. I keep my FC at roughly 4-5 most of the time. If I test at 4 or 5, I usually add bleach to bring it up to 6 to compensate for the next days loss...
I tested Wednesday night and I was at 5. I got busy and forgot to add bleach. We swam Thursday and I had the cover off for about 2 or 3 hours. I tested thursday night and had a FC of 4.5. I didnt add any bleach. I tested Friday evening. Still have a FC of 4.5. I decided not to add any bleach then either. We swam for a few hours yesterday and last night I tested and I was at 4.
I had been adding bleach every day or so up until now. But the last 3 days, i've stayed at roughly 4 without adding anything.
But it seems if I add bleach to get it from 4 to 6, it loses FC back down to 4 within a day. At my current CYA level, is 4 some kind of magic number????
It seems like the FC will drop from 6 to 4 in 12 hrs, but once it hits 4, it stays there longer.
Does this make sense?