Diatomaceous earth (DE)
How it works:
Able to trap anything larger than 2 microns, this type of filter gives you the cleanest pool water out of the four types. Diatomaceous earth, the medium used in this filter, is made up of fossilized remains of a type of hard-shelled algae, and each grain has microscopic holes running through it to trap even the finest particles. DE filters have internal elements that become coated with DE. It is this ‘filter cake’ that strains dirt, dust, algae, and some forms of bacteria from the water.
Pros:
- Filters down to 2 microns
- Large surface area requires less maintenance
Cons:
Needs to be backwashed as well, though not as often as sand filters
- Costs to replace DE each time you backwash it
- Time and effort to replenish the DE powder in the filter
Glass pearls
How it works:
One of the newest filter media on the market, Glass Pearls offer a filtration level comparable to DE. Made from pure glass, the Glass Pearls filter out anything larger than 3 microns, giving you superior quality water.
Pros:
Small effective size of only 0.6mm to 0.8mm. Its narrow particle size range allows very effective in-depth filtration
- Spherical shape of beads means less friction levels inside the filter and therefore requiring only 20% of the water you would use to backwash a sand filter
- Chemically inert, safe, smooth and high purity
Cons:
- Still requires backwashing occasionally
- More costly than sand and Zeoplus
Zeoplus
How it works:
ZeoPlus is a naturally occurring mineral rock, found in areas where there has been historic volcanic activity. Its microporous structure and ammonia removal properties will significantly improve the quality of your swimming pool water. Ammonia is released in the water by bathers and when the ammonium ions mix with chlorine, chloramines are formed, producing a ‘chlorine’ odour as well as causing skin and eye irritations.
Pros:
- Superior water clarity to sand
- Reduced chlorine demand, reducing ‘chlorine’ odour
- Highly recommended for teaching pools and hydrotherapy pools and spas, where the tendency to build up ammonia by products is strongest
Cons:
- Still requires backwashing occasionally
- More costly than sand
- Requires regeneration to continue to retain its ammonia removal properties