I had some iron particles on the bottom of the pool which stained the plaster. Most of the iron was vacuumed up and washed out of the cartridge. I had my water tested for iron and it did not register on the Taylor test.
I added 2 lbs of citric acid (SeaKlear), followed the directions, and it cleared the stains. However, it did not say my chlorine would be depleted. I learned that here. I tested for FC last night and was shocked that it was at 1.5 where it was 10 the night before. I added 2.5 gallons of 12.5% bleach and ran the filter for several hours. FC=15.5.
Question: How much chlorine will the ciritc acid use up?
I want to perform and overnight FC test because I'm worried about having the pool at FC=1.5 for 24 hrs. But don't want to do it until I'm sure the cirtic acid is all used up or else I'll be going crazy.