how many sq ft pool filter do i need

How Many Sq Ft Pool Filter Do I Need?

Summer is fast approaching, and you're eager to enjoy some relaxing pool time. However, before diving into the water, it's essential to understand the importance of a pool filter to maintain a clean and safe swimming environment. Choosing the right pool filter size depends on the size of your pool and its requirements. This article will guide you on how to calculate the necessary square footage for pool filters to keep your pool crystal clear.

The Importance of a Clean Pool

A clean pool is crucial in ensuring an enjoyable and safe swimming experience for everyone. Not only does a dirty pool look unappealing, but it also poses health risks. Bacteria and algae in the pool can cause skin irritations, infections, and gastrointestinal illnesses. That's why pool maintenance is critical to minimize these hazards.

How Pool Filters Work

Pool filters work by removing unwanted debris and impurities from the water as it circulates through the system. Three types of filters are commonly used:

1. Sand Filters

Sand filters are the most popular type of filter used in residential pools. They consist of a tank filled with sand that traps debris and dirt particles as water passes through. Sand filters are low maintenance and suitable for pools with moderate to heavy use.

2. Cartridge Filters

Cartridge filters have a removable cartridge filled with filtering media that captures debris as water passes through. They are easy to install, clean, and maintain, making them a popular option for smaller pools.

3. Diatomaceous Earth Filters

Diatomaceous earth filters are the most efficient option, trapping both small and large particles. They work by using a powdered substance made from the fossils of diatoms, a type of algae, to filter out impurities. Although the most expensive option, they require less maintenance than sand and cartridge filters.

Calculating the Required Size of Pool Filters

To determine the necessary square footage for a pool filter size, you need to know your pool's volume or total gallons of water. The formula to calculate the pool's volume is:

Pool Volume = Length x Width x Average Depth x 7.5

The number 7.5 is multiplied to convert cubic feet to gallons, which is the base unit of pool water measurement. For example, suppose you have a pool that measures 20 feet in length, 10 feet in width, and an average depth of 5 feet. By using the formula above, the pool's volume is 20 x 10 x 5 x 7.5 = 7,500 gallons of water.

Next, you need to determine the turnover rate, which is the time it takes for the pump and filter to circulate the pool's entire water volume. The recommended turnover rate for residential pools is eight hours. To find the required flow rate for your pool's filter, you need to divide the pool's volume by the turnover rate and then multiply the result by 60 (to convert hours into minutes).

Filter Flow Rate = Pool Volume / Turnover Rate x 60

Using the example from above where a pool has a volume of 7,500 gallons and a turnover rate of eight hours, the required flow rate would be:

Filter Flow Rate = 7,500 / 8 x 60 = 937.5 gallons per minute

After knowing the required flow rate, you can then select a pool filter suitable for your pool's requirements. Pool filter sizes are measured by square footage. A general rule of thumb is to have one square foot of filter area per 10,000 gallons of water, although it can vary for different types of filters.

Selecting the right pool filter size makes all the difference in achieving a clean and safe swimming pool. Remember to choose the right type of filter, calculate your pool's volume, determine the turnover rate, and select a pool filter size that meets your needs. With these simple steps, you can sit back and relax in your clean and refreshing pool all summer long.