Lots of factors.
Lots of foliage around the pool that falls in will kill chlorine.
Lots of 'bathers' in the pool kill the chlorine.
Add lots of skin care products and the chlorine is sapped fast.
I have a lot of foliage and spend about $200 per year on chemicals.
Electricity? I have no clue.
I clean it myself.
I maintain myself.
But things break..... So I would add it all up to $100 per month-ish on the high side.
Much lower if you have a good healthy pool with newer equipment.
$50/month would be the low side.
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