How much wet on average should we expect our swimming pool to lose? Per day or week ?

Per day or week ?
Answers:    if the temp is around 100* and you havea 15ft x 30ft pool just about up to 1 inch a day a short time ago for evaporation, also add river that is splashed out and what family take near them going up and out on the stairs and ladder. A leach at the pump will cause alot of river loss. That other guy don't know jack about pools!
you can find out a integer called the "potential evaporation" for where on earth you live. From memory (I read it about 20 years ago) I contemplate this is for example about 900mm per annum within Perth , and in the Simpson Desert it is roughly speaking 3000mm per annum. Another way of interpreting this digit is the amount of water that would evaporate from your swimming pool per annum. It is regularly expressed as mm per day.
If potential evaporation exceeds rainfall you failure up with a mioisture deficit for agricultural purposes