I just want to thank you for the information in Pool School, and useful advice on this forum. A week into the BBB method and the pool is once again crystal clear! I'm coming off shock levels. Here are tonight's readings after a sunny day:
CC 0.5 (probably less - just a SLIGHT pink tint that one drop took to clear)
I had read 60 last week, testing the CYA at night, and did it this evening out in the light outdoors. I now read right at 40, which matches what I expected to have after a 25% water change a week ago. I think lesson I learned is not to test in a kitchen with just overhead lights at 10pm! I think more ambient light helped me see the dot longer. Anyway, I shocked at a TC level of 18, thinking the CYA was 60. Oh well...
Question, do I want to shock longer to get that CC level to 0? No algae anymore, water is sparkling clean. I will probably backwash the DE out again in the morning.
Will the CC go to 0? Like I said, it was just the barest hint of pink before adding one drop to make it clear again. I've been shocking for about a week, but only had the TF-100 kit since Friday, and have seen the CC reading bounce between 0.5 and 1.0 most of the past few days. This is the lowest I've seen it, i.e. less than 0.5.