Why the time matters
On Spain’s regulated tariff (PVPC), electricity costs a different amount every hour, and the dearest hour of a day can cost more than twice the cheapest. The pool pump is one of the appliances that runs longest in a home with a pool, so moving it to the cheap hours shows on the bill without filtering a minute less.
In recent years, with so much solar power, midday hours are often among the cheapest and 19:00 to 22:00 among the dearest. But it changes every day, which is why we check it live.
How many hours should you filter?
The classic summer rule: roughly half the water temperature (with water at 26 °C, about 13 hours a day in total, which can be split). In spring and autumn fewer are enough, and in winter, if the pool is not winterised, a few hours a day. What matters is that all the water goes through the filter at least once a day.
Is filtering at night a problem?
Not for the water: the filter cleans just as well at any hour. Two things to bear in mind. With a salt chlorinator, chlorine is only produced while the pump runs, and in heatwaves part of the filtering should be during the day; that is what the two-run option is for. And if the pump is near bedrooms (yours or the neighbours’), it is more noticeable at night.
Setting the timer
On a pin timer, push down the pins for the hours we suggest. Check the timer shows the right time: the clocks go back on the last Sunday of October and many pump timers do not change on their own.
Frequently asked questions
What if I have solar panels?
Then the cheapest option is to filter while you generate, usually around the middle of the day. This tool is for the electricity you buy from the grid.
Does it work on a free-market tariff?
You pay a different price, but the market’s cheap and dear hours are usually the same, so our suggested time almost always suits you. If your tariff has fixed peak, standard and off-peak bands, use its off-peak hours.
How much does a pool pump use?
Its power times the hours it runs: a 0.75 kW pump running for 8 hours uses 6 kWh a day. This tool shows what that energy costs today.