Activated Filter Media (AFM)
AFM is a patented filtration media developed by Dryden Aqua over more than 30 years, manufactured from recycled green and brown post-consumer glass — the glass types that contain the metal oxides required for the activation process. Activation creates a stable mesoporous surface with a significantly larger effective surface area than conventional filter media. As a result, AFM mechanically retains fine particles more efficiently, while also adsorbing fine particles that are extremely difficult to remove with conventional media. Its engineered particle shape enables proper bed expansion during backwashing, so trapped particles are released efficiently without leaving residual deposits in the filter bed. AFM is also engineered to inhibit biofilm formation and reduce bacterial attachment. This helps prevent media clumping and channelling, allowing the filter bed to maintain consistent hydraulic performance over time while reducing the risk of downstream water quality issues. AFM is a direct replacement for sand or standard glass media and can be used in existing filters without modification. Due to its lower density, around 15% less AFM is required compared to sand.
Key Features:
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- Filters down to 1 micron
- Electro‑mechanical filtration with a hydrophilic, electrically charged surface
- Biofouling-resistant surface — inhibits biofilm formation and bacterial attachment
- Certified for drinking water applications
- Up to 80% better performance than sand or crushed glass
- Supplied in 21 kg bags or 1‑tonne bulk bags
Which AFM grade do you need?
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- AFMng Grade 1 is the main filtration grade for most systems. Grade 2 works as a combined support and filtration layer, and Grade 3 is a support layer that covers the filter laterals to keep flow even during filtration and backwash.
| Product | Role | Filtration performance | Bag size |
|---|---|---|---|
| AFMng Grade 1 | Main filtration layer | Removes 95% of particles down to 1 μm | 21 kg |
| AFMng Grade 2 | Support and filtration layer | Removes particles down to 5 μm | 21 kg |
| AFM Grade 3 | Support layer over the filter laterals | Even flow during filtration and backwash | 21 kg |
- By comparison, high-quality silica sand removes 95% of particles only down to around 20 μm in independent IFTS testing.
Dryden Aqua are finalists in the product category at the European Business Awards with the Activated Filter Media (AFM) that replaces sand in sand filters. Most of our drinking water is filtered by sand, and simply by changing the sand to AFM will double the performance of the filters. What does this mean…? in the developing world AFM could eliminate water based parasitic infections which account for nearly 25% of all disease. AFM can filter down to 1 micron with no pre-coagulation or flocculation, to physically remove parasites. AFM is being used in more and more aquaculture applications. Bulk order discounts are available. Fresh By Design are the official AFM distributors for Aquaculture and Aquaria in Australia and New Zealand
Does AFM work in salt water?
Yes — AFM suits fresh water, seawater and brackish systems, and is used across aquaculture, aquaria and RAS. Its biofouling‑resistant surface inhibits biofilm formation, which matters most in warm, nutrient‑rich marine systems.
What does “ng” mean
“ng” stands for “Next Generation.”
AFMng uses an enhanced activation process that further modifies the surface chemistry of the glass. This creates a biofouling-resistant surface that inhibits bacterial growth and biofilm formation, and improves the removal of fine particles, organic matter and microplastics. The result is cleaner water and more stable long‑term filtration performance compared to standard sand or glass media.
Sizing and ordering
Media volume depends on your filter dimensions and flow rate — as a rule, allow around 15% less AFM by weight than the sand it replaces. Not sure which grade or how much you need? Talk to us and we’ll size it for your system. AFM sits within our mechanical filtration range. If you’re removing larger solids ahead of the media bed, see our drum filters.
