It is important to buy the best pool pump with the correct size for your in-ground swimming pool. People might think that it is better and safer to just buy a bigger pump. However, these pumps cost a lot more and they are not ideal for your filter system. Therefore, a pump you need should be the one that filters all the water in a pool in eight hours. In this article, we will provide details on how to size a pool pump.
Step 1: Determine the number of gallons of water
The first thing you need to do is to calculate the number of gallons of water in your pool.
- For a Rectangular pool
If you are having a Rectangular pool, you need to measure its length and width in feet. Then you need to determine the average depth which is simple. It is the total of the depth at the shallow end and the depth at the deep end that are divided by two. To calculate the total gallons in your rectangular pool, you just need to follow this formula: Gallons = Length x Width x Average Depth x 7.5.
You need to know the number of gallons of water
- For a round swimming pool
In order to know exactly how many gallons of water in your round pool, you need to measure the diameter of your pool as well as the average depth. The average depth is determined in a similar way to the rectangular pool. This is the formula you need to follow: Gallons = Diameter x Diameter x Average Depth x 5.9.
- For an oval swimming pool
It is also simple to calculate the amount of gallons of water in your oval pool. You need to determine the average depth, the longest diameter and the shortest diameter of the pool. Then you will know the total gallons by following this formula: Gallons = The longest diameter x the shortest diameter x Average depth x 6.7.
- For a kidney-shaped swimming pool
If you are wondering how to size a pool pump for a kidney-shaped swimming pool, you still need to figure out the amount of gallons of water in it first. All the measures that need to be done include the largest width, the smallest width and the average depth. The formula for you is: Gallons = (The longest width + The shortest width) x Length x Average depth x 3.38.
Step 2: Determine the GPH (gallons per hour)
When you know the amount of gallons in your swimming pool, your next step is to know what the GPH is. It is also simple to calculate this flow rate, you just need to divide your calculated gallons by eight. In addition, if the pool pump you are looking at has its specifications expressed in GPM, you can still easily convert from GPH to GPM by dividing the GPH by 60 minutes.
Step 3: Determine the average Feet of Head
The Feet of Head decides a pump’s flow rate. It is the height that a fluid will be pumped. In other words, it is the measurement of resistance working when your pump pulls water and then pushes it back to the pool. When buying a new pump or replacing your filter, the system’s feet of head needs to be calculated correctly to find the best fit. So how to calculate feet of head pool pump?
You will find that measurement in every pump curve chart. And you need to use the GPM to calculate your pool’s feet of head. You need to measure the lengths of all the pipes, along with the dips, turns, twists, filter, valve or heaters. The total feet of head will be the sum of those figures.
Step 4: Check the description page
As you have all the information you need, you need to check these info on the description page of the pool pump you are going to purchase. The easiest way to look at a chart that shows all the technical info of the pool pump.
Step 5: Check the size of your pool filter
Your pool filter can’t be too small for the pump, because it will cause additional strain on the pump motor and eventually burn it out. The filter you select can be a little bit oversized to handle the flow coming from the pump.
There are still other things you need to consider when you don’t know how to size a pool pump. But those mentioned calculations are the main configuration you need to purchase the correct pool pump.