How Do Pool Pumps Work?

Adding a pool to your backyard is both an investment and a commitment for a homeowner. A beautiful clean pool can only last as long as it is taken care of properly. Proper pool maintenance relies on knowing what kind of pump you have and how it works to keep your pool glimmering.

How Pumps Clean Your Pool

Pool pumps are centrifugal pumps, which means that they use water moving away from its center force, with both an inlet and outlet for water circulation. The pump creates a centrifugal force by creating a high velocity of water and propelling it to create a vacuum. As air is exhausted from the vacuum, the volute velocity changes, creating energy. This energy pushes water through the pool’s filtration system.

Parts of a Pool Pump


The impeller is the moving part of your pump and is composed of an inverted blade that spins quickly to propel water at a high velocity.


The pump motor is attached to the impeller, and the motor shaft spins the impeller to speed up the water drawn into the pump.

Pump Housing

The pump housing consists of a pump basket and a strainer. The basket collects debris from pool water to prevent damage to the impeller. The strainer keeps the housing air-tight so that air can be exhausted and water flow re-established. When the pump is turned on, water is added to the strainer where the impeller creates a vacuum that moves the water through the filter.

Size Requirements

Turnover rate

Sizing your pool pump is dependent on the turnover rate, which is the rate at which your pump can filter the entire volume of your pool. The turnover rate is measured by gallons per hour (GPH) or gallons per minute (GPM). Your pump size should be determined by the GPH of your pool over an eight-hour period. Make sure not to choose a pump with a GPH below what you need for your pool.


How fast your pool pump turns over water is measured in horsepower. The more horsepower the pump has, the less often you have to run your pump and for shorter periods of time. The size of your motor and the size of your filtration pipes should complement each other. A powerful pump can overwhelm a smaller filtration system.

Motor Voltage

Pool pumps run on electricity and can be either be hard-wired to your home’s electricity or be plugged into an electrical outlet. Pumps typically run on 110 volts or 220 volts.

Types of Pumps

After determining the size of your pool pump, your next step is choosing the type of pump that will work best for your needs.


These pumps are the most affordable and most popular pool pumps. Single-speed means that the motor turns the impeller at one available speed according to the horsepower of the motor. Since this pump operates at only one speed, it can need a lot of energy to efficiently turn over your pool water.


Double-speed pumps can operate at a low or high speed. The high speed is equal to the speed of single-speed pumps, and the low speed is much lower to use less energy.


For a long-term investment in your pool, you may want to consider a variable-speed pump. They have a higher installation cost but can save you a lot of money on energy costs in the long run. These pumps use the same kind of permanent magnet motor used in electric cars. This type of motor causes less friction, allowing the pump to work more efficiently. Variable-speed pumps use less power to turn the water over more quickly.

California Requirements

California Title 20 states that single-speed pool pumps must have a motor capacity of less than one total horsepower (THP). It also states that any pumps with a motor capacity larger than 1 THP must operate at two or more speeds. This means that most single-speed pumps are not compliant with California requirements for privately-owned pools.

Your pool pump will play a key role in protecting the investment in your pool. With a dependable and efficient pump, you can keep your pool sparkling clean while saving on the energy costs for your backyard oasis. Remember to consider your needs and your area’s compliance regulations when choosing your pool pump.