This may be related to the stain removal and chelating treatments I used last week, but my chlorine is really not lasting well! Another possible chlorine eater was the plant matter blown into the pool by the storm. We had a powerful storm Friday night/Sat morn; there was hail, we had a tree knocked down, and there was debris all over the yard and blown onto the house.
Despite its enclosure, my pool had a share of debris; it's not a tight building. I expect an outdoor pool would have been a lot worse! It only took me about 45 minutes to clean up the leaves, etc.
Let me see. . . I don't have my logbook in front of me, but I did check the chlorine Friday night before the storm. I think I topped it up to 4.5. When I tested the chlorine Saturday it was almost gone--0.2 or less. I topped it up to 9 on Saturday night. Sunday morning FC was 7.4; Sunday evening it was 3.6!
I have been adding borax to the pool (along with acid to offset the pH rise), but that shouldn't affect the chlorine, should it? I've added a total of 3 boxes of borax (4lbs 12 oz each) and almost a gallon of muriatic acid.
Also have been running the solar heater.
This morning FC was around 2.8. Not much overnight loss, but I've been having so much Cl loss during the day, I added 2 qts bleach to increase the FC by 3.
Maybe it'll stop eating Cl; I'll see what the FC looks like tonight. Just wondered if anyone had any ideas what could have caused such a Cl demand. . .