Pumps & Filters

Size it so the pump can turn the whole pool volume over about twice a day. Divide your pool volume in cubic metres by the number of hours you plan to run the pump to get the flow rate you need in cubic metres per hour. A 25 m³ pool run for eight hours needs roughly 6 m³/h. Bigger is not better — an oversized pump pushes water through the filter too fast to clean it properly.

For most above-ground wooden pools, yes — sand filters need less frequent attention, cope better with leaves and grit, and the media only needs replacing every three to five years. Cartridge filters filter marginally finer and waste no water backwashing, which makes them a good fit for smaller pools or where water use matters.

Six to eight hours a day in the swimming season is a good baseline, ideally covering the warmest part of the day. Increase it during a heatwave, after a party, or after heavy rain. If you are running a heat pump, the circulation pump has to be on for it to work, so set both schedules together.

When the pressure gauge sits about 0.3–0.5 bar above the pressure you noted when the media was clean — not on a calendar. Backwash for around two minutes until the sight glass runs clear, then rinse for 20–30 seconds before returning to filter. Backwashing more often than needed just wastes water and chemicals.

Drain both completely before the first frost. Remove the drain plugs from the pump and filter housings, open the multiport valve to a mid position, and store removable parts somewhere dry and frost-free. Water left in a housing over winter expands as it freezes and cracks the casing — it is the most common avoidable pool repair we see.