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Swimming Pool Filter Media

Filtration is a very important part of your swimming pool, a pump is used to draw the water into the filter where it is purified by flowing through the top pipe and up and out of the rose at the top of the filter, then as it flows down the debris is caught in the sand and the water flows into the laterals, up the pipe and back through the multiport and back into the swimming pool. As described in the diagram.




Swimming pool sand filter media

Sand is the oldest and more commonly used form of media in a swimming pool filter. In domestic sized filters one grade of sand and one grade of gravel are usually used and in larger sized filters and commercial filters two grades of sand and one grade of gravel are usually used:

  • Sand media grade 0.5 - 1.0 mm

  • Gravel media grade 2 - 3 mm


Sand media, in the past, was known to be the cheaper filter media, but it should be replaced every 5 years, whereas glass media need only be changed every 10 years.​


The problem with sand is that over time it becomes clumped which then produces channels in which the water can run straight through. In some cases where there is hard water the sand can calcify causing it to turn to sandstone.




Swimming pool glass filter media

Glass filter media for filters comes in different types ranging from recycled glass beads, virgin glass beads and impregnated glass with claims that is helps in algae reduction.

The glass is first washed and decontaminated and then carefully broken into appropriate shapes and sizes relating to the three grades used in the filter.

The advantages of using glass as a swimming pool filter media:

  • Better for the environment.

  • Gives a better filtration which gives a clearer swimming pool.

  • Requires less back washing.

  • Saves money on water.

  • Saves money on chemicals.

  • Lasts for approximately 10 years.


Whilst we can report good results using the basic recycled glass, (as detailed above) we do not have enough experience to back up manufacturers claims of the more expensive products.

Workings of a swimming pool filter




AFM - Activated Filter Media

AFM - Activated Filter Media.

AFM is a biological resistant material made out of a specific sized, pure brown and green glass. 


It is subjected to a three step activation process which increases its surface area by 300 times, therefore being able to filter down to 4 microns, half the amount that sand media can.


The benefits of using AFM:

  • Crystal clear water - 30% better filtration than sand media.

  • Lower consumption of chlorine - the better filtration the lower the chlorine demand.

  • No chlorine smell -  AFM prevents biofilm growth, therefore eliminating trichloramine.

  • No Legionella - Biofilm is a bacteria that can provide a home for pathogens such as legionella.

  • Saves on water - less backwashing required.

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