Pool Filter Sand

Pool filter sand is specifically designed to effectively screen out micro particles that end up in your pool during regular usage.  The level of filtration is determined in large part by the quality and condition of the sand so it's important to use a sand that will keep your pool clean and free of dirt and debris all season long.  There are few important things you should know about including the best replacement sand as well as some new and innovative filter sand alternatives on the market today. 

pool filter sand

A sand filter will work at its peak efficiency when the sand is clean and new.  If you were to look at sand under a microscope you would see jagged edges on all sides of the sand particle and it's these jagged edges that act to catch and effectively prevent unwanted debris from returning to your pool.  

Sand gets worn out as water constantly passes through it in a pool system and will cause rounding of the edges that catch the small particles.  As sand begins to wear out you will start to notice your pool getting cloudy and it just won't be as clean.  Another reason your sand filter will falter is if the sand begins to clump or calcify which can occur with poor quality of sand.  

A backwash will remove the particles that collect in the sand but it won't renew the jagged shape that gives it filtering capabilities so it's important that you replace worn out sand approximately every 5 years. 

salt water pool maintenance guide

Pool Filter Sand Specifications

Now that we have explained how pool filter sand works and the importance of using the right kind of sand in your pool we'll go over some of the specifications you should keep in mind when purchasing replacement sand.  All sand is not created equal and spending a bit of time researching reputable products can save you time and money down the road as well as many years of crystal clear water. 

The first first thing to determine is how much sand you need to replace the existing sand in your filter.  This could range anywhere from 50-500 lbs so be sure to check the manual or do some research for your specific sand filter.  It's common to find pool filter sand sold in bags of either 25 or 50 lb bags and it's always a good idea to get a bit extra especially if ordering online. 

You want to find sand that has the following properties and preferably sand that is specifically refined for swimming pools:

  • #20 silica sand
  • 0.45-0.55 mm granules

The #20 silica sand can also be referred to as 20 grit or 20 grain.  If you use a smaller grain you will run into problems with the sand particles ending up in your pool and possibly causing damage to other components in your pool plumbing system.  If you use a larger grain you will be lowering the quality of filtration because small dirt or bacteria particles won't get filtered properly.

It can seem like it's not a big deal and you might think that all sand is the same but you really need to be careful if you purchase sand from a hardware store.  If you plan on using sand that isn't made for pools be sure that it can be used in pool applications.  Unfortunately they probably won't be able to tell you if there are any additives or the quality of the sand and you will be taking a risk. 

Pool Filter Sand Alternatives

In recent years there have been a few new products appear that claim to be a better alternative to regular pool filter sand.  The size and function remain the same as #20 silica sand but the materials are different.  The cost is also a bit higher but with the increased lifespan and improved filtration it is worth it for some pool owners. 

Zeolite Filter Media or Zeosand

Zeosand is steadily gaining popularity with pool owners including salt water pool owners for the many benefits when combing zeolite with salt water.  The results of using it with a salt water system are amazing and will create incredibly clear water and it acts exactly the same way that sand does but better. 

The zeolite media filters debris down to 5 microns which means you get the level of filtration of a D.E. filter without the cost or maintenance of an expensive filter system.  An added benefit is that zeosand controls chloramine formation although this isn't an issue in salt water pools.  You can plan on spending half as much time backwashing compared to regular pool filter sand. 

You can also use about 50% less product if you replace your old sand because it is half as dense.  If your current sand pool filter requires 100 lbs of sand you will only require about 50 lbs of zeosand.  This means you will have to transport less product and will be doing your part to help the environment due to less backwashing.

Zeolite filter media is an all natural product with no added chemicals so when you dispose of it you can use it as you would fertilizer.  The lifespan is similar to regular pool filter sand and should last about 5 years with normal use.  A few of the other advantages of zeosand include:

  • Improved filtration
  • Easy to use
  • Biodegradable
  • Superior water quality
  • Reduces water waster
  • Environmentally friendly

The upfront cost is a bit higher than you would spend on normal sand but all the added benefits, low maintenance and filter quality make it worth it in the long run.  It's sold in 50 lb bags and definitely worth considering especially if you are a salt water pool owner. 

Recycled Glass Filter Media

Another new addition to the world of pool filtration is recycled glass.  We don't need to explain how good this is for the environment but we can say that in addition to providing a use for all the glass in the world it also reduces water waste when backwashing.  

The recycled glass filter media is manufactured to have the same size and quality of regular pool filter sand that is #20 and about 0.5 mm in size with a few added benefits.  The most impressive is the fact that glass has a negative charge that will actually attract micro particles in addition to filtering it more effectively.  More of the filter media will be used compared to sand that tends to only use the top 4-6 inches in most sand filters. 

It is most popular with indoor pools because of its ability to prevent chloramines where air quality is an issue.  It also appears to produce crystal clear water compared to regular pool filter sand and for some commercial pool companies it is the new filter media of choice. 

If there wasn't enough benefits to list there is maybe the most important one and that is it lasts a long time.  It's estimated that the recycled glass will last 10 or more years with regular backwashing and cleaning.  Let's take a look at the benefits compared to regular sand:

  • Exceptional filtration
  • Attracts micro particles
  • Lasts longer
  • It won't clump or calcify
  • Clearer water
  • Shorter backwash times
  • Increased air quality
  • Environmentally friendly

The downside is the same as zeobrite in that it will cost a bit more up front but with the increased lifespan and lower density you just won't need as much.  When you take into consideration all the benefits it's arguably the best alternative to regular pool filter sand we have ever seen and it's a recycled product.


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