Pool Pumps 101: Run Time, Turnover and Variable-Speed Savings
How long to run your pump, what "turnover" means, and why running a variable-speed pump slower and longer can cut its energy use dramatically.
Key takeaways
- Aim to filter the full pool volume about once a day.
- Pump power drops with roughly the cube of speed — half speed uses a fraction of the energy.
- Run slow for filtration; speed up only for cleaners, spillovers, heaters or skimming.
- Most replacement in-ground pumps sold in the U.S. today are variable-speed by regulation.
The pump is the heart of the pool. It pulls water through the skimmers and drains, pushes it through the filter, heater and sanitizer, and returns it to the pool. It is also usually the biggest energy user on the equipment pad — which is why how you run it matters.
Turnover: the number to start with
One “turnover” means the entire volume of the pool has passed through the filter once. Most residential pools are happy with about one turnover per day. Heavily used pools, pools with lots of debris and pools fighting a problem need more.
Example: a 20,000-gallon pool running at 40 gallons per minute moves 2,400 gallons an hour, so one turnover takes a little over 8 hours. Find your volume with the pool volume calculator.
Why variable-speed pumps save so much
Pump energy follows the “affinity laws”: flow drops in proportion to speed, but power drops with roughly the cube of speed. Cut the speed in half and the pump moves about half the water while drawing a small fraction of the power. Running slower for longer delivers the same turnover for much less electricity, with quieter operation and better filtration.
Use a low speed for most of the day’s filtration, and schedule short higher-speed periods only for what needs them: suction or pressure cleaners, spillovers and water features, solar heating, or a skimming boost after storms.
Regulations changed the market
Since July 2021, U.S. Department of Energy efficiency standards for pool pumps have effectively required variable-speed motors for most replacement in-ground pool pumps. If you are replacing an old single-speed pump, expect to install a variable-speed model.
Signs your pump needs attention
- Loud grinding or screeching: worn motor bearings.
- Air in the pump basket: a suction-side leak — often the lid o-ring or a loose fitting.
- Water dripping under the pump: a failing shaft seal.
- Trips the breaker or will not start: call a qualified technician; do not keep resetting it.
Still have a question about this?
Ask a Pool Tech
