Without a good pump, a pool turns stagnant and nasty rather quickly. Pumps circulate water and help filter out bugs, bacteria, dirt, and other things nobody wants to swim with, and keeps water clean and inviting. Weeding through pool pump sizes and features is somewhat overwhelming, so here are a few guidelines to help you spend less time shopping and more time swimming.

Top Pick

This unit can siphon through 1,600 gallons of water per hour. Intex

Knowing your pool’s water capacity is important because you want all the water “turned over” (cycled through the filter system) every eight to 10 hours. The pool pump’s description should specify how many gallons per hour (GPH) it pumps. To figure if the pump will run all the water in your pool through the system every eight to 10 hours, divide the total number of gallons in your pool by the pump’s GPH efficiency. If the dividend is between eight and 10, the pump is large enough for your pool.

This model works for a wide range of water volumes. Intex

The flow rate (GPH) is the amount of water that can move through a pump in a given amount of time. However, it’s also important to know the diameter of a pump’s pipe. A 1.5-inch diameter intake line has a flow rate of about 2,500 GPH, whereas a 2-inch diameter line is closer to 4,380 GPH. The numbers are important because you don’t need a pump with more power than your plumbing lines can handle.

Also Consider

This powerful machine has an extra-large debris basket. Hayward

Most pumps use a specialized type of sand in their filtration components. Water flows through and the sand strains out dirt, algae, and other debris. Some pumps use sand cartridges, which are easy to replace on a routine basis. Other pumps use filter baskets that grab large bits of debris before it can even reach the sand, which can extend the life of a sand filter.