Well, I added 'more' bleach last evening than previously - a couple of hours after adding the bleach last night I was getting :

pH=7.6, FC=27ppm

this AM testing gave:

pH=7.2, FC=15ppm

Question! The best guess chart gives a 'SHOCK" level of 15ppm and a '+SHOCK+' level of 30ppm for CYA=30-50 (my CYA=50), so is a FC level between 15 and 30ppm OK as a target under 'swamp' conditions?

Pic of the pool this AM:



Thanks!