I'm mostly just curious because my chlorine use has been amazingly constant for the past several days. I test every morning around 8 AM and my target is 5 ppm. The FC at 8:00 AM has been 3.5 for the past eight days in a row and adding 3 quarts of 6% bleach brings it to 5 ppm exactly. The other parameters are also very constant:
I can't tell you how pleased I am with the information I've received on this site. The water is as clear as clean glass and I have not had to shock it or kill algae since I started following the suggestions here.
I still have yellow stains that I'll have to try to remove using the ascorbic acid method, but I've been putting it off hoping they would just go away.