$100 a month to a pool guy who keeps my pool crystal clean and in perfect balance. I pay $80 every 6 months for a filter cleaning/ Replacement/maintenance check-up . I built my pool two years ago and have not had any additional expenses.

As far as energy bill, I don’t notice any difference, maybe 5$ a month at most...but we don’t heat our pool. My pool filter is very energy efficient, runs at 80 watts most of the day (similar to 1-3 lightbulbs) and 2000 watts for an hour every night.