Is it possible to maintain "unsafe" free chlorine levels at a given CYA ppm?
Excluding jumping in right after one shocks, of course
For example, let's say a pool has a CYA of 20 ppm. At night the owner shocks the pool to 12 ppm, per the BG chart.
The next day, after the sun has been up for several hours, the owner jumps in.
I've been under the assumption that the pool should be safe, as the CYA will protect and hold chlorine up to the max level in the chart, and the excess will have been lost to the sun. Right? Or can the CYA actually protect and hold a higher chlorine level than what is indicated in the max column, potentially creating an unsafe condition?