The last time I was in my pool store (by my pool store, I mean the one that sold me the pool); the line was backed up with people needing sample testing and they all had problems with their pools. They had an associate with the chemicals helping people in addition to the testing associate. In other words, they are so busy trying to fix people's pool woes, that they had to double team it. I could hear some of what the helper was telling customers. She was mostly giving good advice regarding what kind of chlorine to use based on the particular customers' stabilization level, except that, of course, they were not recommending higher FC levels based on CYA, and that is the big, big problem even with the best-intended and most knowledgeable pool store staff in my opinion. I asked the customer in front of me. She was constantly having problems this year--cloudy and green; keeps coming back. Did not own a test kit. Just brought in samples when the pool would lose clarity. I recommended that she go to the website, learn, get a kit and start doing it herself, but I didn't know her CYA level, so I couldn't get specific. I did tell her that she was probably not keeping enough chlorine in the pool and probably not putting enough in when shocking, because the industry's recommendations are generally low on both accounts to keep pools clean, but that's all I could say w/o knowing her numbers.
I was there getting a sample tested while I had started with TFP, but was still waiting on a TF-100 and my current test kit had only PH, total chlorine, and TA, so I wasn't totally on board with the TFP system, but was on my way at the time. Alot of people just keep pucks in the pool; run the filter; and brush and vacuum now and then, and then when the pool gets cloudy or green, they'll run a sample to the store and get help. They think that's the way pool care has to be. As long as their pools are relatively clear, they think everything is just fine.
I had recently used dichlor for a period of time as my daily chlorine add because I needed to raise my CYA just a little, but not 5 lbs worth of CYA. Since, during the interim of getting totally set up for TFP and not exactly knowing how much I had added to my CYA, I was being conservative on my FC level and keeping it between 4-7. I was showing 3 ppm loss per day, so I figured I was either over estimating my CYA, or had CC's coming on. At least by the pool store test, it was the former. My CYA was only 33, according to their test. I went home and started using the rest of my dichlor with daily adds, watching PH and TA of course. When I got my kit, my actual CYA was at 45 and I had used the calculator to move CYA to 48, which I knew from prior experience would not move it as much as the calculator stated; either due to dilution or specific product properties or whatever. At any rate, I got the CYA where I wanted it, but would have been much easier had I gotten the kit sooner.
Anyway, this is thread about high chlorine. The tester guy handed my report to the manager. He looked at my report with FC @ 6.1 (it was a mid-morning test and I had moved my FC close to 7 using an OTO the evening before--I know, not very accurate). Anyway, he said to cut down on my chlorine use, because it was too high. I said "thank you". I couldn't argue, because he was partially right, because my CYA was only @ 33. But I bet, that if my CYA had been 60, he'd had said the same thing. And then, I would have argued with him.
