You may not know that your pool pump uses more electricity than any other appliance in your house except your air conditioner. You also may not know that most pools are equipped with pumps that are too big and use way more energy than you need to keep the water sparkling clean.

The culprit: the single-speed pump. A small one is probably fine if all you want to do is circulate the water in the pool. But it might not have enough speed to run your pool cleaner, waterfall or other electrical extras that need an occasional, bigger blast of energy.

If that’s the case, your pool service probably installed a pump that’s large enough to handle the extras. But if it’s only got one speed, it’s running full-blast even when your pool cleaner and waterfall aren’t operating—with no option to dial back to a lower level of energy when all you need is to turn the water over, which is most of the time.

That’s a huge waste of energy, and it’s costing you about 80 percent more in electric bills than you should be paying.

Don’t let the high cost of running your pool outpace its value as your family’s go-to place for fun, relaxation and keeping cool this summer. Making your pool more energy efficient will shave hundreds of dollars a year off of the cost of operating it. Some things to consider:

1. Replace your single-speed pool pump with a variable-speed unit. New, high-performance models from manufacturers like Pentair Water Pool and Spa and Hayward Pool Products let you run them on low most of the time and crank them up bit by bit only when you need more power to run your accessories.

The manufacturers claim the pumps can cut energy use by up to 90 percent compared with single-speed pumps. A fellow i know who owns Desert Sun Pools in Phoenix, says his customers who have switched report saving $300 or more a year on their electric bills.

A variable-speed pump costs more than twice as much as a single-speed model, but you’ll recoup the extra cost in lower electric bills within two years, he estimates. Plus, he says, the pumps are quieter and last longer than older pumps.

As an alternative, two-speed pumps cost less than variable-speed models. And although they’re not as efficient as variable-speed pumps, they use far less energy than the single-speed unit that’s probably in your pool now.

2. If you’re an APS customer, wait until March 15 to buy your new pump. That’s when the utility will start offering $200 rebates on variable-speed pumps and $100 back on dual-speed models.

Bring your electric bill to a participating pool service or store to prove you’re an APS customer. You’ll find a list of participating stores at www.APS.com starting on March 15.

3. Sign up with your electric utility for a “time of use” rate plan; both APS and SRP offer them. You’ll pay a reduced rate for electricity if you run your pool pump and other appliances—like your dishwasher or washing machine—during hours of the day when demand for electricity isn’t at its peak.

Example: SRP will cut your “off-peak” rate from the standard 11 cents per kilowatt-hour (a measure of electricity use) to around 6.5 cents if you run your pool pump and other appliances between 8 p.m. and 1 p.m. during the summer. If you run the devices between 1 p.m. and 8 p.m., you’ll pay more to use the same electricity.

SRP estimates that time-of-use customers save up to 7 percent on their electric bills. 

4. Run your pool pump less. It’s not necessary to run it around the clock. Most manufacturers recommend running it between eight and 10 hours a day in the summer and about half that in the winter.

5. Put a timer on the pump so it automatically shuts off after those hours, and set it to run only when you’re paying off-peak rates.

One of the APS rebates that starts on March 15 is for a seasonal timer that you can program for a monthly decrease in how long your pump runs each day from September through February. The TightWatt seasonal timer, made by Allen Concepts in Chandler, can qualify for a $75 rebate.

6.  Switch to LEDs, which use up to 75 percent less energy than your traditional incandescent underwater lights. LEDs last for years and come in multiple colors as well as white.

7. Keep your chemicals in balance. If you don’t, your filter can run all day and night and the water will never sparkle. 

8. Clean trap baskets, filters, and pool walls and floor regularly. Clogged baskets and filters can prevent the water from flowing freely, and will slow your filter down. The harder the pump has to work to keep the pool clean, the more you’ll pay to run it.

It costs around $125 to have a pool service come out and test the level of “total dissolved solids” like calcium in the water and determine whether you need to drain and refill your pool.Another option is to bring a sample to your local Shasta Pool or Leslie's store.