The Water Cycle
Water in a Pool
A Carbon filter, used to remove the ozone from the water
All ozone must be removed once it has purified the water. This is done by passing the water through one of two common media. The carbon also removes any organic contaminants.
GAC, granular activated carbon is most commonly used. It has a microporous surface of 1000m2/g, with a bed depth of 0.5m. It is produced by steam treatment from a coconut shell, coal or wood.
Another type used is unactivated heat treated anthracite or coal with a lower adsorbant surface area of less than 500m2/g, the bed depth is 0.7m. This does make it less efficient than GAC.