How Does a Pool Sand Filter Work? A Guide

As the name suggests, a pool sand filter uses sand to filter pool water. The water passes through a chamber filled with sand, trapping particles, debris, and other contaminants. The purified water flows out of the sand filter and back into the pool.

Using sand for water filtration dates back to civilisations as early as 2000 B.C.! In the last few decades, sand filter technology for swimming pools has become more popular because it works well and costs less than other pool filters.

A pool sand filter uses silica, quartz, or garnet. These natural materials are proven to trap dirt and debris from water. They also help to improve water clarity and reduce chemical usage in pools.

The ancient use of natural materials to filter water can give you confidence that a pool sand filter is an excellent choice for keeping your swimming pool clean and safe for the whole family to enjoy!

Pool filters trap dirt, debris, and other contaminants in pool water. How?

1. Pool water enters through an inlet pipe into the filter tank.
2. Contaminants are trapped as the water flows through the filter media (or material).
3. The clean water exits through an outlet pipe at the bottom of the filter tank.

How does a pool sand filter work? Silica sand (the most commonly used sand for pool filters) is made up of hard, angular granules that are incredibly effective at trapping and filtering particles from water. Silica sand can filter particles down to 20 microns (approximately 0.0008 inches).

A pool sand filter has several settings and controls that regulate its operation.

• Pressure gauge. Measures the water’s flow rate, or pressure, as it enters and exits the filter tank.
• Multiport valve. Multiple ports inside this valve allow water to move in various directions for cleaning or backwashing.
• Timer. Controls how often the filter cycles.

You can determine if your pool sand filter is working by checking the pressure gauge. The pressure reading (PSI) should be between 10 and 25. The normal operating pressure of your pool depends on how big and powerful your pump is and how clean your filter is. If the pressure is 10 PSI higher than usual, your filter needs cleaning through backwashing. 

If the pressure is 5 PSI lower than usual, water isn’t flowing through the filter quickly enough. Most likely, there is a blockage somewhere before the filter. Make sure no leaves, twigs, or other debris is blocking your skimmers, drain covers, pump basket, or impeller. 

You can also check to see if your filter is working properly by looking at the water. Your filter needs attention if there is a buildup of dirt and debris in your pool.

By understanding how pool sand filters work, you can make an informed choice for your swimming pool filter.

Maintaining a pool sand filter is relatively straightforward. Regular backwashing helps keep your filter functioning correctly and can extend its lifespan. Backwashing means running the water in the opposite direction, causing the dirt and debris that were being filtered to be cleared out of the filter media and sent back out of the drain.

Most filters should be backwashed once every month or after heavy use. Before you start a backwash, you need to turn off the pump and clean out the skimmer basket.

If you backwash your sand filter too frequently, it may become overly clean and not be able to capture finer particles effectively. This happens because finer particles have a greater opportunity to bounce around and break down when they come into contact with the already-dirty particles present in the filter. As a result, it is important to avoid backwashing too often to ensure that your sand filter functions optimally.

In addition to backwashing, the sand in a pool sand filter needs to be replaced every 7 to 10 years, depending on usage and the state of the water. The sand should be changed all at once, because adding new sand on top of an old layer won’t do a good job of filtering.

Lastly, you must use the correct sand for your filter. Not all sands are appropriate for filtration, so always consult the manufacturer’s instructions for specific recommendations on the sand type.

At Hy-Clor, we recommend our Zeo-Clor product as the best choice for your sand filter. It’s an all-natural, environmentally safe sand filter media that works in all sand filters. Zeo-Clor provides superior water clarity as it filters finer than regular filter sand. It draws ammonia out of pool water, increases the efficiency of other pool chemicals, and cuts backwashing by up to 50%.

Regularly maintaining your pool sand filter ensures that it functions correctly and your pool water stays clean and clear.

Hy-Clor high-rate sand filters offer outstanding performance for domestic swimming pools. They are made from a corrosion and chemical-resistant material, which ensures their durability and longevity.

Our pool sand filters come in either a 19-inch or 24-inch size. Both are suitable for

• Chlorine pools
• Salt pools
• Above-ground pools
• In-ground pools
• Spas
• Swim-spas

For price details, please fill out our online enquiry form.

A sand filter is an excellent choice for keeping your pool water clean and safe. This naturally derived filtration system is affordable, effective, and relatively easy to maintain. Remember – being proactive with pool maintenance will save you time, money, and energy in the long run!

We are one of the biggest companies in Australia and New Zealand that sells pool chemicals and equipment. Wondering how a pool sand filter work? We’re here to help. Our team of experts at Hy-Clor will help you discover how our high-rate sand filters can provide the perfect filtration for your pool.

For more information, get in touch with us today via our online enquiry form. Alternatively, please visit your nearest Bunnings Warehouse for our full range of products.