🔷 AFM® NG Activated Filter Media – Grade 2 – 21kg Bag

🌊 Superior Support Layer Filtration for Crystal Clear Pool Water – Bio-Resistant, Self-Sterilising & Certified

📋 Product Overview

AFM® (Activated Filter Media) Grade 2 is a highly engineered filtration media manufactured by Dryden Aqua from carefully selected green and brown soda-lime-silica glass. Unlike standard crushed glass or traditional sand, AFM® undergoes a unique 3-step activation process that fundamentally changes the surface chemistry and structure of the glass at a molecular level.

This activation process creates a self-sterilising, bio-resistant surface that prevents bacterial colonisation, eliminates biofilm formation, and stops the clumping and channelling that plagues conventional filter media. The result is consistent, predictable filtration performance that maintains its effectiveness for the life of your filtration system.

AFM® ng (Next Generation) Grade 2 serves a dual purpose: it acts as both a support layer and an active filtration layer, removing particles down to 5 microns. When used in combination with AFM® Grade 1, it creates an optimised filter bed structure that delivers industry-leading water clarity whilst reducing chemical consumption and maintenance requirements.

Designed for swimming pools, hot tubs, spas, and commercial aquatic facilities, AFM® Grade 2 is a direct replacement for traditional sand media, requiring approximately 15% less product by weight due to its lower bulk density.

⭐ Key Features

✅ Bio-Resistant Surface Technology – The activated surface prevents bacterial growth, eliminating biofilm, mud-balling, and the clumping that degrades conventional media performance over time.

✅ Dual Function Support & Filtration Layer – AFM® ng Grade 2 doesn’t just support the upper filtration layers; it actively filters particles down to 5 microns, maximising your filter’s overall efficiency.

✅ Self-Sterilising Properties – Metal oxide catalysts on the activated surface generate free radicals, creating a zone of high oxidation potential that prevents bacteria from colonising the media.

✅ 97% Backwash Efficiency – Independently verified by IFTS to release retained particles efficiently during backwash, preventing the accumulation of organic matter that causes filter degradation.

✅ Sustainable & Eco-Friendly – Manufactured from 100% recycled post-consumer glass bottles in an ISO-certified facility powered by self-generated solar energy.

✅ Guaranteed 10+ Year Lifespan – Dryden Aqua guarantees performance within 10% of “as new” after 10 years. AFM® typically lasts for the life of the filtration system.

✅ Certified for Drinking Water – NSF/ANSI 50 and NSF/ANSI 61 certified by WQA for swimming pools and potable water applications.

✅ 15% Less Media Required – Lower bulk density than sand means you need approximately 15% less AFM® by weight to fill your filter.

🔧 Technical Specifications

Specification	Grade 2 Value	Standard
Product Type	AFM® s / AFM® ng	–
Particle Size	0.7 – 2.0 mm	ISO 13322-2 / EN 12902:2004
Effective Size (d10)	0.80 – 1.0 mm	ISO 13322-2 / EN 12902:2004
Undersized Particles	≤ 10%	ISO 13322-2 / EN 12902:2004
Oversized Particles	≤ 10%	ISO 13322-2 / EN 12902:2004
Uniformity Coefficient (d60/d10)	1.3 – 1.8	ISO 13322-2 / EN 12902:2004
Sphericity (Average)	0.80 ± 0.03	ISO 13322-2 / EN 12902:2004
Roundness	0.65 ± 0.05	ISO 13322-2 / EN 12902:2004
Bulk Bed Density (Uncompacted)	1.40 kg/l ± 0.03	EN 12902:2004
Specific Gravity (Grain)	2.4 – 2.52 kg/l	GTS QP9
Hardness	5.5 – 6.5 Mohs	ASTM C-730
Acid Solubility	< 0.2%	EN 12902:2004
Loss on Ignition (LOI)	< 0.03%	EN 17978:2024
Bag Size	21 kg	–
Colour	Green/Brown (recycled glass)	–
Material	Activated soda-lime-silica glass	–

Chemical Tolerance

Parameter	Range
pH Range	pH 4 to pH 10
Temperature Range	0°C to 100°C
Free Chlorine Tolerance	Up to 10 g/l
Chlorine Dioxide Tolerance	Up to 10 g/l
Ozone Tolerance	Up to 10 mg/l
Hydrogen Peroxide Tolerance	Up to 10 g/l
Salinity/TDS	No physical or chemical effect

📊 Grade Selection Guide

🎯 Choosing the Right AFM® Grade for Your Filter

AFM® is available in multiple grades designed to work together for optimal filtration performance. The correct combination depends on your filter diameter.

Grade	Particle Size	Function	Filtration Performance
Grade 0	0.25 – 0.5 mm	Extra fine filtration	98% removal down to 1 micron
Grade 1	0.4 – 0.8 mm	Main filtration grade	95% removal down to 1 micron (ng)
Grade DIN	0.7 – 1.2 mm	Special media for high TSS loads	96% removal down to 4 microns
Grade 2	0.7 – 2.0 mm	Support & filtration layer	Removes particles down to 5 microns
Grade 3	2.0 – 4.0 mm	Support layer (covers laterals)	Flow distribution support

Recommended Grade Combinations

Filters < 800mm (31″) Diameter:

• 50% AFM® Grade 1 (main filtration layer)
• 50% AFM® Grade 2 (support & secondary filtration layer)

Filters > 800mm (31″) Diameter:

• 50% AFM® Grade 1 (main filtration layer)
• 25% AFM® Grade 2 (support & secondary filtration layer)
• 25% AFM® Grade 3 (base support layer over laterals)

📐 Quantity Guide

🧮 Calculating AFM® Requirements

AFM® has a lower bulk density than sand (approximately 1,250 kg/m³ vs 1,500 kg/m³ for sand). This means you require approximately 15% less AFM® by weight compared to sand.

Sand to AFM® Conversion

Sand Required	AFM® Required	Reduction
25 kg	21 kg	15% less
50 kg	42.5 kg	15% less
75 kg	64 kg	15% less
100 kg	85 kg	15% less
150 kg	127.5 kg	15% less
200 kg	170 kg	15% less

Example Calculation

If your filter manufacturer specifies 100 kg of sand:

1. Calculate AFM® quantity: 100 kg × 0.85 = 85 kg total AFM® required
2. For filters < 800mm diameter:
   • 50% Grade 1 = 42.5 kg (approximately 2 × 21kg bags)
   • 50% Grade 2 = 42.5 kg (approximately 2 × 21kg bags)

⚠️ Note: Always check your filter manufacturer’s specifications for the recommended media depth and quantity. The above is general guidance based on Dryden Aqua recommendations.

💎 Performance Benefits

Superior Filtration Performance

AFM® has been independently tested and verified by IFTS (Institut de la Filtration et des Techniques Séparatives) – Europe’s leading accredited laboratory for water filtration media. Key findings include:

• AFM® ng Grade 1 removes 95% of particles down to 1 micron at 20 m/hr flow rate without flocculation
• AFM® removes 99.6% of particles down to 5 microns – compared to just 72.97% for equivalent grade sand
• AFM® performs more than twice as well as sand for sub-5 micron particle removal
• 97% backwash efficiency – matching sand whilst outperforming all other glass media tested

Chemical Reduction Benefits

• Up to 50% reduction in chlorine demand – Superior filtration means fewer particles requiring oxidation
• Up to 50% reduction in THMs (trihalomethanes) – Less organic matter means fewer harmful disinfection by-products
• Elimination of chlorine smell – Reduced trichloramine formation improves air quality

Backwash & Water Savings

• Up to 50% reduction in backwash water – More efficient cleaning cycles
• Backwash efficiency of 97% – What goes in comes out, preventing organic accumulation

Health & Safety Benefits

• Significantly reduces infection risk from bacteria and parasites including:
  • Legionella
  • Pseudomonas
  • Cryptosporidium
• No biofilm formation – Eliminates the protected environment where pathogens thrive

Longevity

• Guaranteed minimum 10-year lifespan with performance within 10% of new
• Expected to last the life of the filtration system when used according to specifications
• No performance degradation – Unlike sand which becomes a biofilter within months

🎯 Real World Applications

🏊‍♂️ Residential Swimming Pools

Perfect for domestic pool owners seeking crystal-clear water with reduced chemical consumption. The combination of AFM® Grade 1 and Grade 2 transforms standard sand filters into high-performance filtration systems, removing particles invisible to the naked eye whilst cutting chlorine usage significantly.

🏢 Commercial & Public Pools

Ideal for hotels, leisure centres, water parks, and public swimming facilities where water quality standards are paramount. The bio-resistant properties ensure consistent performance under heavy bather loads, whilst reduced chemical requirements lower operating costs and improve air quality for swimmers and staff.

🛁 Hot Tubs & Spas

Excellent choice for hot tubs and spas where elevated temperatures and concentrated bather loads create challenging conditions for filtration media. AFM®’s self-sterilising properties prevent the bacterial growth that conventional media cannot resist, ensuring safer, clearer water.

🌿 Ponds & Water Features

Suitable for ornamental ponds, water features, and natural swimming pools where maintaining ecological balance is important. AFM®’s superior filtration removes fine particulates whilst its chemical-free bio-resistance means no harmful leaching into the aquatic environment.

🏭 Aquaria & Aquaculture

Used worldwide in public aquariums, marine mammal facilities, and aquaculture systems where water quality directly impacts animal health. AFM® provides the fine filtration needed for sensitive species whilst maintaining the biological stability essential for life support systems.

🔄 Installation Notes

🛠️ Converting from Sand to AFM®

Pre-Installation Checks

1. Inspect filter internals – Check laterals and distribution systems for damage before filling
2. Calculate media requirements – Use 85% of sand weight specified by manufacturer
3. Determine grade combination – Based on filter diameter (see Grade Selection Guide)

Installation Steps

1. Half-fill filter with water – This protects the laterals during media addition
2. Add AFM® Grade 3 first (for filters > 800mm) – Creates the base support layer
3. Add AFM® Grade 2 – The support and secondary filtration layer
4. Add AFM® Grade 1 – The main filtration grade on top
5. Level each layer as you go to ensure even distribution

Post-Installation (Critical for AFM® ng)

For AFM® ng (hydrophobic surface), the media must be properly wetted before use:

• Option 1: Submerge in water and soak overnight (>12 hours) before first backwash
• Option 2: Rinse to drain for >10 minutes at >15 m/hr flow velocity
• After wetting, perform initial backwash until water runs clear

Ongoing Maintenance

• Backwash weekly (minimum) or when pressure differential indicates
• Backwash at sufficient velocity to achieve minimum 20% bed fluidisation
• Backwash duration: Minimum 5 minutes or until water runs clear

⚠️ Professional Installation Recommended: For optimal results and to ensure warranty coverage, we recommend professional installation by a qualified pool technician.

📥 Downloads & Resources

📄 IFTS Report on AFM – Independent performance test results comparing AFM® to sand and other glass media (PDF) Download IFTS Report

📄 Product Brochure EN – Comprehensive overview of AFM® benefits and applications (PDF) Download Product Brochure

📄 Installation Manual EN – Step-by-step media replacement and installation instructions (PDF) Download Installation Manual

🏆 Why Choose AFM® Grade 2?

✅ Proven Performance – Independently verified by IFTS to outperform sand and all other glass media in filtration efficiency, particle retention, and backwash performance.

✅ Self-Sterilising Technology – The only filter media with an activated surface that actively prevents bacterial colonisation, ensuring consistent performance without degradation.

✅ Dual-Purpose Design – Grade 2 works as both support and active filtration layer, maximising the efficiency of your entire filter bed.

✅ Exceptional Value – Whilst initial costs may be higher than sand, the 10+ year lifespan, reduced chemical costs, lower backwash water consumption, and elimination of media replacement deliver significant long-term savings.

✅ Certified Quality – NSF50 and NSF61 certified for swimming pools and drinking water. HACCP certified for food and beverage production. Manufactured under ISO 9001, ISO 14001, and ISO 45001 certified management systems.

✅ Environmental Responsibility – Made from 100% recycled glass in a factory powered by self-generated renewable energy. A true circular economy product.

🛒 Why Buy From Parts4Tubs?

At Parts4Tubs, we’re passionate about helping you achieve the best possible water quality for your pool, hot tub, or spa. When you buy from us, you’re not just buying from the internet – you’re buying from real people who understand your needs.

✅ Expert Knowledge – Our team has hands-on experience with hot tub and pool systems, so we can provide genuine advice and support.

✅ UK-Based Business – We’re a UK company (Amandi Holdings Limited) based in Northamptonshire, with local customer service and support.

✅ Fast UK Delivery – We dispatch quickly so you can get your system up and running without delay.

✅ Secure Payment – Shop with confidence using Visa, Mastercard, PayPal, Apple Pay, Google Pay, or Stripe.

✅ Built on Trust – Parts4Tubs was built on the success of buildahottub.com, bringing years of experience in the hot tub and pool industry directly to you.

✅ Real Support – Questions? Get in touch – we’re here to help you find exactly what you need.

✨ Summary

AFM® Activated Filter Media Grade 2 represents the pinnacle of filter media technology, delivering exceptional support-layer filtration whilst actively removing particles down to 5 microns. When paired with AFM® Grade 1, it creates a filtration system that outperforms sand by more than double, whilst resisting the biofouling that degrades conventional media.

With independent verification from IFTS, NSF certification, and Dryden Aqua’s 10-year performance guarantee, AFM® Grade 2 is the smart choice for pool owners and commercial operators who demand the very best in water clarity, reduced maintenance, and long-term value.

Upgrade your filtration system today with AFM® Grade 2 – where science meets sustainability for crystal-clear water.