Sometimes, when I think of it, I will retest FC an hour or so after an addition if I've just opened a new case regardless of what the label says. It might have sat too long on the dock or something. I learned that lesson the hard way opening up to a hazy pool through no negligence, just weak chlorine.
You know how to do this, Megsy!!!!! It will be much faster this time, especially without the sago organics!!!
You know how to do this, Megsy!!!!! It will be much faster this time, especially without the sago organics!!!