How big a pump do I need?

Q: How big a pump do I need for my pool?

A: Here is a case where bigger probably IS better.

There are generally two uses for pumps in a pool. Jet pumps are used to create a current to swim against and/or to massage aching muscles. These are generally separate from the circulation pumps, which are used to move water through the filter, heater, and sanitizing systems. We’ll talk about the latter.

The typical rule of thumb for circulation pumps is that they should “turn over” all the water at least four times a day, or once every six hours. So, if you have a 3,000 gallon pool, you would need a pump that would move 500 gallons per hour (500 gallons/hour x 6 hours = 3,000 gallons).

Unfortunately, the rule of thumb for human pools doesn’t apply to canine pools. We have loads more hair to deal with, not to mention the dirt and dander.

I recommend a minimum of one turn every 3 hours, and more definitely is better. My pool turns over in less than an hour. This means that if I get a particularly “dirty dog” client who leaves the pool water looking a bit cloudy, it will be clear and clean again in no time.

The tricky part about choosing a pump is that they are usually listed as having a particular horsepower (HP), but this doesn’t really tell you how much water they will move. This is because a pump’s capacity depends on many factors, one of which is how hard it has to work to move the water. This is impacted by such things as the type of filter, how clogged it is, the size of the pipes, and how high the water outlet is above the inlet. All of these factors are added together to calculate what is called the head . Head is expressed in feet, and it comes from the amount of energy it takes to raise a column of water one foot high.

This is where a knowledgeable pool technician is helpful. They can look at your system and make a pretty good determination of what the head is likely to be. They should then consult the pump performance curve to determine which pump will operate both effectively and efficiently for your setup. Depending on the design and efficiency of the pump, a 3/4 horsepower model may move more water than a 1 horsepower model, and will require less electricity to do it!

Happy swimming!

Answer courtesy of:

The ACWT Pool Guru:
Karen Hunter
22609 102nd Ave SE
Woodinville , WA 98077
425 487-3078