pool sand vs play sand

Pool Sand vs Play Sand (Is Play Sand the Same as Pool Filter Sand?)

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Pool filter sand is one of the more expensive sand options around. As a mom of sand-loving kids and owner of a sandbox, I can assume it can be tempting to simply use play sand in your pool filter.

sand for swimming pool
Swimming pool is so much fun, but it can be an expensive to have one

After all, they look more or less the same. Unfortunately, the term ’sand’ covers a massive range of materials, and there is quite a big difference between play sand and pool sand. It’s just like comparing play sand and paver sand.

What’s The Difference Between Pool Sand and Play Sand

Usually, when you compare similar products to a ‘made for kids’ version, you find that the kids’ version is the highest quality alternative. However, this is a situation where that’s not true.

pool sand vs play sand
Left: pool sand | Right: play sand

In terms of processing and quality, much more time, energy, and money go into pool sand than play sand.


The most obvious difference when you compare these types of sand is the size of the grains.

Pool filter sand has a much smaller particle size. They are no more than half a millimeter in diameter. This small size allows them to trap even very fine matter. Particles as small as 20 microns can be filtered out of your pool water, all because of the small particle size.

In comparison, the particle size in play sand is around 2 millimeters. When the grains are 4 times bigger, they cannot catch as much debris if used in a pool filter. They are small enough to be pleasant to handle and to use for making sandcastles, but they are just inadequate for effectively cleaning your pool water.


The composition of play sand can vary depending on which sort you buy. Most play sand is made of quartz, also known as silica. The percentage of silica will depend on where the sand came from and how it has been treated. There are also play sands which are silica free, so they contain other minerals such as feldspar instead.

Pool filter sand is exclusively made up of silica. Silica is very effective at removing impurities from pool water. It is also quite effective at maintaining the pH. 

You can often tell the difference in composition simply from the color of the sand. Pool Filter sand tends to be quite a distinctive color – usually white, but it is pink or green on occasion. Play sand is typically a brown ‘sandy’ color. This is due to the presence of the feldspar particles. While this makes it okay to play in, it does reduce its efficacy as a filtration media.

How Pool Sand Filters Work

Palmetto Poolfilter-50 Superior Pool Sand Filter – 20# Grade – Formula, One Size, 50Lb-A

Sand filters work using the same principles as most other pool filters. The water is pushed down through the filter. As the water particles pass through the sand, they become attached to the silica. These form an even finer mesh that traps the impurities in the water. This mesh can capture everything from soil and hair to body oil and sweat.

As sand filters collect the dirt from the water in the sand, they eventually become full of this first. When this happens, the flow drops, and they stop cleaning the water. When this happens, you can often improve the situation by backwashing the sand. To do this, you send water in the opposite direction through the filter. Most of the dirt is then expelled from the sand. There is, however, a limit on the number of times you can do this and have it be effective.

Why Change Pool Filter Sand?

Pool filters work by catching all the muck from your pool water. That dirt all collects in the sand of your filter. In the short term, this can make it more effective. The extra layers of dirt actually help it to trap more and more unwanted items from your water. However, there is a limit to how much your pool sand can hold. 

Once you reach the limit of the sand in your filter, two things begin to happen. The first is that the rate of water flowing through the filter drops. The second thing is that the water that does go through the filter is not cleaned as well. The end result is that the pool filter is no longer able to perform its job correctly.

change pool filter sand
Don’t forget to change your pool filter sand!

When To Change Pool Filter Sand?

If you get high-quality silica sand for your pool filter, it can last anywhere between 5 and 15 years. So even though it can be expensive to buy the right sand, it really is worth it. The chances are high that the sand you get will last as long as your filtration system, so you can almost consider it a permanent filtration media.

However, there are some circumstances under which you may need to change your pool filter sand.

  1. After installing a new filter – If you install a new filter, you should fill it with fresh sand. You don’t want to transfer the sand from your old filter to the new one. This is a recipe for problems. It’s best to just start over with new sand.
  2. Your pool water is dirty or cloudy – This indicates that your pool filter is not working as it should. If you have a sand filter, the first thing to try is changing the sand to see if that improves the situation.
  3. After an extended period of heavy use – If you use your swimming pool a lot, you may want to consider replacing the sand after around 3-4 years.

Can You Put Too Much Sand In A Pool Filter?

Sand filters shouldn’t be overfilled. Most work best when they are only ⅔ full. Before filling yours, you might want to check the company’s website to find thor recommendation. If you overfill your filter with sand, it can reduce water flow through the filter and make it ineffective.

Can You Use Play Sand In A Pool Filter

play sand is not good for swimming pools
Play sand is not recommended for swimming pools

It is not advisable to use play sand in your pool filter. The larger particle size and different chemical compositions of play sand mean that much of the dirt and debris in your pool water will just pass through the filter. It just isn’t very effective at cleaning your pool water.

Is Pool Filter Sand Safe For Aquariums?

You may know about play sand for aquariums, but what about pool filter sand? It turns out that pool filter sand is actually an ideal substrate for aquariums. It’s an excellent option for people who have animals that like to bury themselves at the bottom of the tank.

Pool filter sand is safe for your animals, and it looks very natural in a tank. The best pool sand is #50-grade sand. This is fine enough to be gentle on your fish while being coarse enough to resist clumping.

Pool filter sand can work out as a cheaper option than aquarium sand, and it still offers all the same benefits, so if you have some on hand, it really is a good alternative.

Frequently Asked Questions

What is the best sand for a pool filter?

The best sand for a pool filter is pool filter sand. It has a high silica content which allows it to trap impurities in the water. It also consists of exceedingly fine grains. These tiny grains effectively filter all sorts of debris from the water without impeding the flow of water.

Palmetto Pool Sand Filter
Palmetto Pool Sand Filter
Helps prevent unwanted dirt from pools by filtering the water with natural sand that's perfectly sized for filtration.

How much sand to add to pool filters?

Your pool filter should not be completely filled with sand. There needs to be space inside the filter. This allows the debris to be caught and for a bit of churn in the system. Usually, the right amount is ⅔ full. However, it can vary between filter brands, so it’s best to check the appropriate company website if you are unsure.

Can you reuse pool filter sand?

The more water that runs through your pool sand filter, the more dirt and debris there will be collected in the sand. There will be particles you can easily see, but there will also be microscopic dirt that you can’t. When it comes time to replace the sand in your pool filter, it is best to simply dispose of the sand. Because it contains large amounts of dirt, it’s best not to leave it lying around. You also shouldn’t reuse it as it could be home to a lot of bacteria.

The best option is to find a spot to bury it in your garden.

Last update on 2021-04-30 / Affiliate links / Images from Amazon Product Advertising API

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