Having your own swimming pool requires ongoing maintenance to keep it clean and running at its best. One important component of this maintenance is your pool filter, which pulls in water that traps dirt and debris from entering your pool. If you don’t properly maintain your pool filter, this can make your equipment work harder, leading to increased electricity bills and extra wear and tear on your pool filtration system.

There are various types of pool filters available on the market, and one of the most popular kinds are sand filters. Learn how sand filters work, as well as how to properly change the sand in your pool filter.

How sand filters work

Sand filters use natural sand as a filtering agent, trapping debris as it passes through so that only clean water is pumped into your pool. One reason for their popularity is that they can last longer than other filters and require minimal maintenance. Sand filters work by allowing water to cycle through a canister that contains sand. The water flows through the sand with ease, but larger particles and debris are unable to pass through at all. Even smaller materials will be stopped as the water from your pool moves through the filter canister. 

Once these particles have been filtered out by the sand, a pump moves the clean water back into the pool. As more debris becomes collected by the filter, the efficiency of the filter actually starts to increase! The added debris helps keep smaller particles from passing through the sand.

Maintaining your sand filter

Occasional cleaning and maintenance is required to keep your pool sand filter working properly. The more dirt and debris inside your sand filter, the more pressure will begin to build within the filter canister. After taking an initial reading of the filter’s pressure gauge when you install it, check it every week or so to see if the pressure has increased. Once the pressure has increased by 8 to 10 pounds, you will need to clean the filter by performing a process known as “backwash cleaning” to remove excess dirt and other debris from the sand. 

How do I backwash a sand filter? It’s easy! Shut down the pump cycling water through the filter and allow it to come to a complete stop. Once the pump has stopped, attach the backwash hose and turn the pump’s setting valve to “Backwash.” Turn the pump on and let it run; the water will start coming out clear and will begin to get darker as more debris comes out. Allow this water to run until it becomes mostly clear again, then shut the pump off, turn the setting valve to “Rinse,” and allow the pump to run a rinse cycle for 30 to 45 seconds. The rinse stage is especially important — otherwise some sand may enter your pool. After completing this process, put up the backwash hose and reset the pump to its normal setting before starting it up again.

What sand is the best for your pool?

There are three main types of sand you can use for your pool sand filter: silica, zeolite and glass sand.

Silica

Silica Sand is made up of the mineral quartz, and is affordable, effective and easy to maintain — even for large pools! Silica is also eco-friendly, free of chemicals, naturally derived and odorless. It is the most common type of pool sand on the market.

Zeolite

Zeolite is a natural and safe mineral found in volcanic rocks. Zeolite sand can filter up to 90% more particles than standard pool sand, which makes your pool even clearer. It is also capable of binding with chloramines to help maintain the chlorine balance in the pool water. 

With Zeolite sand you may not have to backwash as often as with other sand — it still should be done regularly, but you may be able to go an extra week in between. That said, Zeolite is more costly than silica pool sand.

Glass Sand

Made from recycled glass, glass pool filter sand is the best option for removing very small particles from the pool water. Glass sand can capture debris as small as 3 to 5 microns in size, making it a good option for pools with recurring algae problems. Algae spores can be very tiny, allowing them to slip through silica sand and create new problems in the pool.

Whichever type of sand you choose, make sure the sand you buy is labelled as “pool sand” or “filter sand” in order to meet the standard of sand used specifically in pool filters. The wrong type of sand can destroy a pool filter — you can’t just steal some sand from the beach and expect it to work!

How do I know when to change the sand?

Even if you regularly backwash your sand filter, it won’t last forever and will become less efficient as time goes on. Fortunately, if well maintained, you only have to change the sand in your filter every 3 to 5 years. Over time, the filter can get clogged with grime and debris and if you don’t refresh the sand inside, the filter won’t function properly.

If your pool filter requires more filtration, backwash and rinse cycles to get the pool back to the clarity you love, that is a sign that the sand needs to be changed out. If your pool is losing its sparkle, that’s a sign that tiny particles are not being properly filtered out. Old or dirty sand in your filter can make it hard to maintain water at proper levels, and often results in murky or cloudy water which can even make people sick. 

A good time to change your pool filter sand is when you are opening your pool for the season, as the sand will be dry and easier to remove. 

Step by step guide to changing your pool filter sand

Fortunately, changing your pool filter sand isn’t difficult, but it can be a bit time consuming. To ensure the correct steps are taken, here is our step-by-step guide to properly changing the sand in your pool filter.

1. Turn off the pump.

2. Pull drain plug to allow the filter to drain.

3. Remove filter head.

4. Remove sand from the filter. A wet/dry vacuum works well for this.

5. Perform a visual inspection of the area and remove any debris.

6. Rinse out the tank.

7. Reassemble and cover the interior stem and pipe.

8. Fill the tank halfway with water.  

9. Add the fresh sand as indicated on the filter.

10. Reattach filter head.

11. Run system on backwash (as mentioned above).

Of course, you can always leave the hard work to us if you don’t want to change your pool filter sand yourself, and want to have peace of mind that everything has been done correctly. Contact Calais LeisureScapes today for all of your pool maintenance needs! We have the right equipment and know-how for the job. All you’ll have left to do is relax and enjoy your refreshed pool!