I'm new to pool testing and want to know when to test chlorine levels? Should I wait a certain amount of time after there have been swimmers in before testing? Will CC levels be high right after swimmers exit the pool until the FC has had a chance to break it down? The PH is 7.6, CYA level is below 20, TA is 140, FC level is 6 with a CC of 1.5-2 after swimmers got out. It was about 0.5 yesterday awhile after swimmers got out. I need to add acid to drop the TA but I'm not sure what to do with the chlorine. We use chlorine pucks or sticks with a chlorine feeder and it's an indoor 33,000 gallon vinyl pool with a leak in it so I have to add water fairly constantly and it's high in TA so I have to knock the TA down fairly regularly. I use a DPD test kit in a Taylor 2006C kit. My nephew was okay swimming in the water but lately he's been getting quite a rash so I'd like to figure out how to fix it so he can use the pool without staying up all night itching! Any pointers would be greatly appreciated!