How Many Pool Filter Balls Do I Need?

pool filter balls

.Determining Your Pool Size

The first step in calculating how many filter balls you need is to determine the size of your pool. Pool size is typically measured in gallons or liters, and this information is crucial because it directly influences the capacity of the filtration system needed. To find out your pool’s volume, you can use the following formulas depending on your pool’s shape:

1.Rectangular pools:

Length x Width x Average Depth x 7.5 = Volume in gallons

2.Circular pools:

Radius x Radius x 3.14 x Average Depth x 7.5 = Volume in gallons

3.Oval pools:

Half Length x Half Width x 3.14 x Average Depth x 7.5 = Volume in gallons

Make sure to measure in feet for the dimensions and convert the depth into an average if it varies.

.Calculating the Filter System Size

Once you know your pool’s volume, the next step is to determine the size of your filter system, which is typically expressed in terms of flow rate—the amount of water it can process per hour. A good rule of thumb is that your filter system should be able to cycle all the pool’s water within 8 to 10 hours. To calculate the required flow rate:

1. Divide your pool volume by the number of hours (e.g., 8 hours) it should take for one complete turnover.

2. Convert this amount to gallons per minute (GPM) by dividing by 60 (since there are 60 minutes in an hour).

For example, a 24,000-gallon pool divided by 8 hours gives 3,000 gallons per hour, which converts to 50 GPM.

.Calculating the Number of Pool Filter Balls Needed

With the flow rate determined, you can now calculate how many filter balls are required. Pool filter balls are a modern alternative to filter sand, with 700 grams of filter balls being equivalent to 25 kilograms of sand. To determine how many filter balls you need:

1. Check the specifications provided by the manufacturer of your filter system—they usually specify the amount of media required in terms of sand.

2. Convert that amount into the equivalent weight of filter balls.

For instance, if your filter system requires 100 kilograms of sand:100 kg of sand is equivalent to 2,800 grams of filter balls (since 700 grams replaces 25 kg of sand).This means you would need about 4 bags of filter balls if each bag contains 700 grams.

.Maintaining Your Filter Balls

Maintenance of pool filter balls is simpler and less frequent than sand. To ensure their longevity and efficiency:


Clean filter ball

Regularly clean the filter balls as per the manufacturer’s instructions. This can often be done by washing them in a washing machine on a gentle cycle.


Over time, filter balls may become less effective and need replacement. This is typically after a few years of use, depending on pool usage and care.


Switching to pool filter balls can be a great way to enhance your pool’s filtration system with less maintenance and better performance. By following the steps outlined above, you can easily calculate how many pool filter balls you’ll need based on your pool’s size and your filter’s capacity.