I also have a fully exposed AG pool. I have experienced close to 5 ppm losses on the worst of days. my chlorine pump is set up assuming a little over 4. I have to wonder if the absence of a deep end allows for greater losses.
no chlorine loss overnight. i was testing in the morning and again late evening to see what loss there was. seems like my number is acceptable. been a nice summer so far up here in the northeast. sun is hitting the pool at 6AM and still has sun on it at 8pm right now. thanks again, i won't try to increase my CYA right now to combat it.