Pool Care Pool Maintenance

How to Choose a Pool Filter? – A Beginner’s Guide

How to Choose a Pool Filter for your poolMost pool filter buyers go through a lot. Most of the times, because of going blindly, they end up buying the wrong size, type, or even model. And to help you not go through the same and waste your time and money, this guide is for you. I will give you a list of considerations and features to go through before you can make your decision.

8 Useful Tips to Choose a Pool Filter

1) Filter Type

Swimming pool filters come in three major types, namely sand, cartridge, and DE filters. Let’s go through each model.

a) Sand filters

Sand filtersA sand filter uses special sand made from a base compound of silica or sometimes with other organic materials like crushed glass. The sand is kept in an empty tank which is equipped with a multiport valve with multiple positions for multiple functions.

Typically, how it works is, the pump pushes water through the filters sand so that it can catch the debris and then the water goes back to the swimming pool. Sand filters, like the DE, require backwashing frequently to cleanse out the sand and the remains that plug up the flow pipes. To do this, all you need is send the water in reverse to flush it out.

Sand filters clean water about 20 microns, and they last over five years when you need to replace it. They are also cheaper and easy to maintain. However, they do require frequent backwashing, which can lower water level or might alter the pool chemistry.

b) DE (diatomaceous earth) filter

The next type is the DE filter which uses diatomaceous earth matter as its filtration medium. The material is a naturally occurring sedimentary rock crushed into a white powder. The DE filter also consists of a large tank with grids or fingers in it which get coated by the DE powder.

The DE powder filters the swimming pool water similar to sand, but a better job. It removes all the debris down 5 microns. They are considered the best for keeping the water clean and doesn’t require a lot of maintenance compared to the other types.

The DE filters require backwashing and replenishing with a fresh DE powder frequently. If it’s a DE unit using grids, the grids need to be removed and cleaned using hands to get rid of the dust. They are quite easy to clean, conserve water and high on energy efficiency. However, the cartridges require replacement every 3-years and they aren’t ideal for a large pool.

c) Cartridge filter

Cartridge filterLast is the cartridge filters which use replaceable cartridges for the filtration. The filter cartridges remove the debris to around 10 microns. Cleaning is quite easy by hosing them using a high-pressure hose. These types of filters are the most energy-efficient and cost less than the DE filters. It’s a great option if you have a small swimming pool that requires less maintenance. However, you need to know, cartridges need replacement every three years and aren’t ideal for large swimming pools.

2) Filter Size

For optimal filtration, you need to get the right pool filter size. To do that, you need to know your exact pool size. So, how do you find the right size? Most people drop the ball here. Some guess the size and end up buying the wrong model. Here is the ABC you need to use to estimate the right pool filter size for your swimming pool.

First, you need to calculate the volume of your swimming pool. For a square or rectangular pool, you need to multiply the length by width by depth. And for the circular pools, you have to increase the radius by pi (3.14) by depth.

The results here will give you the volume. Convert it to gallons by multiplying the amount by 7.48, which is the number of gallons in a cubic foot. For you to get the water flow rate, you can buy a low-priced hardware sensor. Or you can use the following formula which will cost you nothing.

Water flow rate = pool’s capacity divided by the turnover.

The turnover rate is the amount of time need to circulate the water inside the pool entirely. Typically, it’s around 6-12 hours.

Use the flow rate you got to find the ideal filter for your pool. Keep in mind that you can find the actual flow rate of your pool filter by multiplying your filter rate with the filter area. The bigger, the better.

3) Construction quality

Construction quality of Pool FilterWhen making your choices, you don’t want to forget the construction and durability. For the filter pump to offer you a long term service, you need to make sure it’s well built and with high-quality materials. Since you will be installing the filter outdoors, you must buy a model with high-strength, rust-free, corrosion-resistant, and UV-protected elements.

Additionally, it’s good you ensure that the construction is reliable by looking at the general build. The internal parts also need to be high-quality to make sure they are not affected by the water chemicals.

4) Easy installation

Despite pool filters being complex with all their corresponding parts, many manufacturers offer a detailed installation guide. Yes, you can find a lot of materials to install the pool filter, but you need to get it right. Some filters might take you minutes, and others can take you hours. Mostly the installation difficulty depends on the model you’ve decided to buy.

To make it easy for you, buy a model that is easy to install. You don’t have to spend more of your money, hiring a professional to help you with the installation. With the right model, you should be able to connect it and have it working within no time. But if you are not confident, you should hire someone to do the work for you.

5) Replacement Ease

Some pool filters feature parts that are quite easy to find and fix. Some of the components can be easily found in a local store, while others are much more difficult to locate. I recommend you buy a pool filter that you can repair quickly and media that you can replace easily.

6) Compatibility

Mostly, the adapters connected to the pool filters might make it difficult to join. That happens mostly with old pools. New pool filters feature a design that makes them compatible with an existing pool. Extreme cases will require simple adaptions. You need to ensure you check the pool filter specs to see if it can work with your fittings.

7) Brand and warranty

Most people forget to check on the warranty offered by the brand. Different brands offer different terms of the warranty. The best way to ensure you get the ideal model and a proper warranty is to buy a model form a reputable brand. That way, you’re sure the pool filter is made from quality materials and meets all the safety standards. Above that, you will be confident that they will go through with their warranty policies.

8) Price

Budget is an essential shopping tool. A budget will help you decide on a pool filter that doesn’t go beyond your preserved investment. With the market offering hundreds, if not thousands of options, you will need to have a reasonable budget. While checking for what you’re paying, you also need to check on what you’re you can afford. Yes, quality first, but let the budget decisions. If the budget isn’t a limit for you, then settle with the highest quality and the expensive one.


Choosing a pool filter shouldn’t give headaches anymore. When making your choice, all you have is use this guide as your reference, and the process will be smooth for you. Once you get your ideal pool filter, you have to give the right maintenance for optimal performance and long durability.

About the author

Sharif Miah

Hi! I'm Sharif, the founder of Globo Pool® and I have been working in the pool & hot tub industry for the last few years. I love to share my experiences with people & hope you are enjoying my information and lessons!

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