Activated Filter Media (Dryden Aqua)

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Activated Filter Media (Dryden Aqua)

Activated Filter Media (Dryden Aqua)

AFM® stands for Activated Filter Material, a revolutionary filter media made from green glass, developed and manufactured, and a registered trademark by Dryden Aqua.


  • Exceeds the performance of quartz and glass sand by filtering about 30 % more organics.
  • Bio-resistant and self-sterilising which means no biofilm is formed in the filter bed. This important feature makes the pool system healthier, ecological and more economical.
  • Used in over 100’000 public and private swimming pools worldwide.
  • Manufactured under ISO 9001-2008 standards
  • Certified under European standards for swimming pools and drinking water, NSF50 and NSF61.



AFM® exceeds the performance of quartz and glass sand by far 


1. Crystal clear water:

AFM® filters much finer than quartz or glass sand. At 20 m/hr filtration speed a nominal filtration of 5 microns is achieved without flocculation – AFM® filters at least 30 % more organic substances than fresh quartz or glass sand. With optimised coagulation and flocculation with APF and ZPM, a nominal filtration of less than 0.1 microns can be achieved.


2. Lower chlorine consumption means less secondary chlorine reaction products:

Chlorine is an excellent disinfectant. But in reaction with organic and inorganic substances it also  produces undesirable, harmful reaction by-products such as trichloramine and THM‘s. The more chlorine is consumed the more secondary reaction by-products are produced. With AFM® we can remove far more substances than with sand or glass sand. This applies particularly in connection with coagulation and flocculation. Everything that can be filtered out and removed in backwash process doesn’t have to be oxidised. The better the filtration the lower the chlorine consumption and less disinfection by-products are produced.


3. Bioresistant – no home for bacteria, viruses and other pathogens:

Sand is a good mechanical filter but it’s also an ideal breeding ground for bacteria. Within just a few  days every grain of sand is colonised by bacteria. They immediately form mucus to protect themselves against the disinfectant. In this so-called «biofilm» live entire communities of bacteria and other pathogens – including Legionella. If you have no organic film in your filter there are also no Legionella.


4. No trichloramine and no chlorine smell:

The bacteria in the biofilm convert urea into ammonia which then reacts with chlorine to inorganic chloramine (mono, di- and trichloramine). Trichloramine causes the unpleasant chlorine smell and is also a severe health hazard. If however, no heterotrophic bacteria are present, urea remains in the water. It reacts with chlorine to the harmless chlorine urea. No biofilm – no trichloramine - no chlorine smells.


5. Filter function remains good with AFM® for many years:

No biofilm in the AFM® filter also means no channel formation to disrupt the filter function. Due to filter contamination the performance of a sand filter worsens dramatically after 6 - 12 months despite frequent backwashing. The performance of AFM® remains consistently high for many years.