Just as your heart pumps blood throughout your body, your pool must have a pump to keep it healthy. Here are some things pool owners should know about pool pumps. You will find this information especially beneficial when it’s time to think about replacing your pool pump.
The basic principle of the pump is to move water in your pool. Most people know that, but do you know just how much needs to flow through your pump each day? In the winter you need the water to completely filter through your pump once a day. In the summer that volume of water needs to increase to 1-1/2 times a day.
Your pump consists of two main parts: the motor and the pump head. When your pump stops running you don’t necessarily have to replace both. Frequently the motor fails before the pump fails (though you might have to replace parts in the pump).
There are many sizes of motors. For backyard pools, there are only three sizes typically used. We refer to the different sizes by horsepower: one, one-and-a-half, and two horsepower. As you might guess, the larger the motor, the more water it will pump. Buying a size larger than needed is not necessary, but you’ll regret it if you buy a size too small because a smaller motor will work harder and longer to move the needed volume of water each day.
The good news is when replacing a motor, there is almost always a weatherproof sticker on it indicating the size. Once in a while someone bought too small, so it’s good to have a pool professional confirm that you are replacing the motor with the right size. For that you should know two things: how many gallons your pool holds and the model number of your pump. Of course, it’s likely that if the motor is too small, the pump will be too small too.
There are two main sizes of pumps, medium head and high head. These have to do with a pump’s strength at pushing water through your pool. High head is greater strength which most of the time is needed for pools with in-floor cleaners.
There are two key elements that determine what pool pump will best work for your system (and how strong it needs to be): “flow-rate” and “head”. Flow-rate refers to how much water can be moved in a determined amount of time and is measured in gallons-per-minute (or GPM). The term “head” refers to the amount of resistance to flow that exists in your pool plumbing system. Head is usually measured in “feet of resistance” or “feet of head”. The items in your circulation system (such as a heater, automatic pool chemical feeder, etc.), as well as the amount of bends in your piping, size of piping, and distance the water must travel all play a role in determining your total head.
Is your head spinning yet? Don’t worry, pump manufacturers carry details related to flow-rates and head which will help you determine which pool pump you need. And again, most of the time you will simply be replacing your pump, unless you or a pool professional thinks you might need something larger. This will depend on the difficulty and cost it takes to keep your pool sparkling.
It’s also important to keep in mind that these two calculations, flow-rate and head, are not independent of each other. Your determined/desired flow rate will play a part in determining your head, as many elements within a pool’s plumbing loop offer different levels of head depending on how much water you’re trying to pass through them in any given moment.
Costs relating to pumps are determined by size (power) and what they are made of. There are some inexpensive plastic pumps that are pretty good, but the problem with these is they don’t last as long. Chemicals tend to be harsh on any type of plastic. Of course, if you recently bought a house with a pool from an owner who installed a cheap pool pump you will want to consider upgrading, when it comes time to replace it.