Yikes - something's still using up my chlorine. Tested about 1pm, just 4 hours after this AM's tests and now I have no chlorine, pH still holding. No need to try the distilled water method if I have no chlorine by the regular method. So, I'm adding calhypo (HTH Super Shock It) for the first time, a package made for 16,500 gallons. Says it's 62.4% Calcium hypochlorite with 60% available chlorine. I'll test again in a few hours and see what level we have.

My water temps are still holding in the 82 AM -86 PM range, as our air temps have topped out in the upper 90s and low 100s all week.

Sandy