I did overnight loss test and lost 0ppm FC from yesterday evening to this morning. CC still at 0
Kids swam today for about 3 hours. According to local weather data temp got up to 76F today. Pool gets direct sunlight for a few hours.
I don't remember losing that much FC a day last year.
I recently posted numbers from last night, here they are again:
PH=7.6 (could be 7.8, I'm using a cheap no-name kit for PH right now, have a Taylor on the way).