Thanks. I'm glad this was helpful. By the way, if we assume that your lack of using the pool eliminates the chlorine usage for ammonia/organics/pathogens, then that's 0.5/day less loss so you would end up with 5.8 ppm instead of 3.3 ppm. So you can see how a relatively small change in an assumption can change the end result quite a bit. Of course, with an open pool there is probably junk getting blown into it so the "organics" demand on the chlorine probably doesn't really go to zero.

The main thing is to find a way to get chlorine into your pool while you are gone and then enjoy your vacation! I just got back from vacation myself, but we had someone stay at our house to not only add some chlorine to the pool a couple of times during the week, but also to feed and care for our two cats. The pool is actually a positive draw for someone to stay in our home and its someone we know and trust.

Richard