How long to run your pool pump
There is no single correct number of hours — it depends on your pool volume and your pump's actual flow rate. Work out the turnover time first; everything else is a judgement call on top of it.
One full turnover takes about 5.6 hours at 60 GPM (3,600 gallons per hour).
Two full turnovers would take about 11.1 hours.
Turnover time, in one line
turnover hours = pool gallons ÷ (pump GPM × 60)
A 20,000 gallon pool with a pump moving 60 GPM turns over in about 5.6 hours. That is the physical minimum — the time for the whole body of water to pass through the filter once.
What actually drives the runtime
- Bather load. A pool used daily by a family needs more circulation than one used on weekends.
- Debris and season. Leaf fall and pollen season push skimming demand up.
- Sanitiser distribution. Chlorine needs to reach every corner; dead spots are a chemistry problem as much as a filtration one.
- Local rules. Public and semi-public pools are often governed by a health code that specifies turnovers per day. Residential pools usually are not.
- Running cost. If your utility has time-of-use pricing, shifting the same hours to off-peak can cut the bill without changing the total.
Splitting the runtime
Running the pump in two blocks — for example early morning and late afternoon — keeps chlorine circulating when the pool is actually in use, and can be cheaper on a time-of-use tariff. The total hours matter more than whether they run in one stretch.