A complete guide to deep bed filters with AFM®
Looking for effective ways to improve the efficiency and safety of your commercial pool?
By utilising deep bed filtration systems combined with the beneficial properties of Activated Filter Media (AFM®), you can do exactly that.
This thick layer of long-lasting, granular media upgrades the capabilities of deep bed filters, helping to reduce operational costs and the environmental impact, while maintaining high water quality for a more enjoyable swimming experience.
From the technical specifications to the benefits and practical uses for deep bed filters and AFM® filter media in commercial pools, the experienced team of engineers at Chemsol explain everything you could need to know about using these systems.
Keen to learn more about AFM® deep bed filter configuration or ready to discuss upgrading your sand filtration system?
Speak to Chemsol’s expert team of engineers today!
What is AFM®?
AFM® is a type of engineered glass media specially designed by the leading brand, Dryden Aqua, to capture solids and impurities in water.
This includes visible dirt and debris, as well as microscopic particles, contaminants, organic substances, and pathogens.
Unlike traditional sand, this media is made from a select type of green and brown glass that’s been upcycled from post-consumer bottles. This recycled glass then undergoes a unique activation process, which increases its surface area and negative surface charge.
Finer than normal sand, or generic crushed glass filter media products, AFM® is also self-sterilising, supporting optimised filtration performance, longevity, and reduced chemical usage.
It’s also cost-effective, and biofouling-resistant which helps to combat bacterial growth and reduce harmful by-products and pathogens.
It’s for these reasons AFM® is often used as a superior replacement for traditional sand media in deep bed filtration systems.
It can help increase filtration efficiency and pool hygiene, while simultaneously reducing operational costs, making it a versatile solution across diverse water treatment needs.
Examples of AFM® deep bed filtration applications
Unsure whether this filtration system will work for your commercial pool or water treatment facility?
Key application areas for AFM® deep bed filtration include:
- Drinking water treatment
- Wastewater treatment
- Commercial swimming pools, schools, and leisure centres
- Hotels and spa facilities
- Zoos and public freshwater and marine aquaria
- Aquaculture and fish farming
- Industrial process water treatment
- Pre-treatment for advanced membrane filtration systems
- Iron and manganese removal from water
Types of AFM® used in commercial pools
The term ‘Activated Filter Media’ is a registered trademark of Dryden Aqua and is used to highlight that its glass media has undergone a unique three-step activation process.
While other types of glass filter media do exist and are often superior to the sand alternative, they haven’t gone through the same patented activation process as AFM®.
As a result, they don’t possess the sought-after bio-resistant and self-sterilising properties.
There are two main types of AFM®, which can also be purchased in multiple grades.
Both types are hydrophilic and polar, biofouling-resistant, and can filter 95% of all particles >1μm, but they have slightly different applications:
- AFM® S: Suitable for a wide range of applications, AFM® S is ideal for the efficient removal of heavy metals (including iron, manganese, and arsenic) and oil. It’s also compatible for backwashing with air scouring.
- AFM® NG: This type of AFM® is well-suited to the removal of organics, such as microplastics, oils, fats, and lipids. It offers efficient filtration in both hard and soft water, but in contrast to AFM® S, it’s not suitable for backwashing with air scouring.
How is a deep bed filter with AFM® different to a standard swimming pool filter?
Weighing up whether it’s worth making the upgrade to AFM® from sand?
To help you decide between the two, we’ve created the AFM® deep bed filters vs standard filters table below.
Feature | AFM® Deep Bed Filtration | Standard Sand Filtration |
Filtration performance | Filters very fine particles (down to 1-5 microns) | Filters only larger particles (20-30 microns) |
Clear and healthy water Lower risk of bacteria and by-products | Basic water clarity Higher risk of bacteria and by-products | |
Efficiency | Needs less backwash water and fewer chemicals | Uses more backwash water and more chemicals |
Maintenance | Low maintenance, resists biofilm and clogging | Needs more frequent backwashing and can clog over time |
Life expectancy | Lasts 15-20+ years | Lasts 3-5 years |
Running costs | Lower long-term cost despite higher initial price | Higher ongoing costs despite lower initial price |
Can you replace a standard swimming pool filter with an AFM® deep bed alternative?
Yes, replacing a standard swimming pool filter with a deep bed alternative is certainly possible and often advisable for commercial pool proprietors with concerns about the quality of water filtration.
Most pool plant room installers will recommend complete upgrades – involving the installation of a purpose-built deep bed filter - rather than trying to retrofit a new component into an existing system.
This is because deep bed filters have a taller vertical profile compared to standard beds. While this design allows them to accommodate a greater depth of AFM®, it can make it harder to retrofit.
However, whatever your pool filtration needs might be, we want to hear from you. Our expert team can carry out a comprehensive survey, helping you to understand your options and outline where we can add value to the swimming experience.
What are the benefits of installing deep bed filtration with AFM® in a commercial pool?
Healthier
Deep bed filtration paired with AFM® ensures even the finest particles are captured, reducing the number of contaminants in the water and boosting water clarity and hygiene for a better swimming experience.
Efficient
Thanks to AFM®’s high filtration performance, self-sterilising properties, and reduced chemical demand, it is significantly more efficient than sand. AFM® requires less water for backwashing, fewer chemicals for disinfection, and delivers lower operating costs over time.
Bio-resistant
Self-sterilising, AFM® helps to prevent bacterial growth, which reduces harmful by-products and pathogens, leading to cleaner water, improved air quality, and lower chemical usage.
Crucially, this also reduces the spread of harmful by-products (like trichloramines) and lowers the risk of pathogens such as Legionella and Pseudomonas.
Sustainable
Less backwashing, lower chemical demand, and far less frequent media replacement supports sustainable operation and lower environmental impact of commercial pools.
Long-lasting
Unlike sand, AFM® does not become a breeding ground for bacteria because of its self-sterilising properties. This means it lasts far longer, providing reliable, consistent filtration for 15–20+ years.
How much does deep bed filtration with AFM® cost?
The cost of deep bed filtration with AFM® varies depending on whether you’re purchasing just the media or a full filtration system (complete with professional installation).
AFM® cost
You can expect to spend anywhere between £35-80 for a 21kg bag of AFM®, while the same 21kg bag of sand filter media can be purchased for around £15-£60 in the UK.
However, prices naturally fluctuate by filter media type and grade, as well as retailer. Other factors that can have an impact on the cost of media are explored in the table below by comparing AFM® to the sand alternative.
Cost factor / Filter media | AFM® | Sand |
Media purchase price | Higher | Lower |
Media life expectancy | 15-20 years | 3-5 years |
Maintenance frequency | Less frequent | More frequent |
Chemical use | Reduced | Higher |
Overall value | Long-term savings, but higher upfront cost | Higher long-term running costs, but cheaper upfront price |
Deep bed filter cost
Many residential deep bed pool filters cost in the range of £950-£1500, while larger models designed for commercial purposes can be significantly more, costing upwards of £3000.
The cost of a deep bed pool filter in the UK will also naturally vary depending on the filter’s capacity, manufacturer, and features – and whether you opt for professional installation and ongoing maintenance.
For a more accurate idea of how much a pool filtration system might cost (including design, supply, and install), we recommend speaking to the Chemsol team today.
Potential challenges of installing a deep bed filter with AFM®
Higher initial costs
Both AFM® media and deep bed filter systems have a higher initial cost than the standard sand solutions.
Filter design adjustments
To fully benefit from deep bed filtration, the existing system may need modifications.
This can include adjustments to pumps, valves, pipework, or flow rates to ensure proper filtration and backwashing performance.
Complex installations
Deep bed filtration systems may require professional installation - especially if you’re upgrading from a standard filter.
Space restrictions
If you have limited space in your pool plant room, you may struggle to accommodate the larger size of the deep bed filtration systems.
Advanced training
Your in-house pool maintenance team will need to properly trained on how to maintain deep bed filtration systems and maximise AFM® media’s performance.
For example, AFM® requires less backwashing and must also be loaded correctly for optimised filtration.
Maintaining deep bed filtration systems
Fortunately, the extended depth of deep bed filtration systems means they have a higher dirt capacity and therefore require less maintenance compared to the more conventional sand alternative.
However, deep bed filters still need some degree of maintenance to ensure smooth operation. While frequency of these maintenance tasks varies depending on the media type, these systems typically require:
- Routine backwashing
- Keeping chemicals balanced
- Deep cleaning of filter media
- Monitoring of pressure gauge
- Replacement of filter media
- Straining of pool debris
- Protection from a pool cover
At Chemsol, we offer a range of pool servicing and maintenance solutions.
From fault-finding to repairs, remodels, and control panel programming, we can provide tailored pool maintenance that meets your specific needs.
Whether you require a regular service contract, seasonal pool services, or an emergency call-out, you can trust our professional team to provide specialist pool filter installation, repair, and maintenance when you need it most.
Contact our team today for a quote
AFM® systems and relevant UK pool regulations
AFM® can be used in UK commercial pools, subject to correct system design and adherence to Pool Water Treatment Advisory Group (PWTAG) guidelines and general health and safety law.
AFM® may help meet PWTAG performance expectations under the right conditions by removing finer impurities from the water and reducing the risk of biofilm, as this supports operators with maintaining compliant, safe, and hygienic water quality.
However, under PWTAG guidelines, the use of AFM® does not guarantee compliance or safety. Many other factors including whole system design, maintenance, and operational oversight (in terms of filtration rate, turnover time, and backwashing procedures), will play an important role.
And, as with any commercial pool, those with deep bed filtration systems and AFM® media must follow essential regulatory and safety considerations, such as
- Maintaining correct disinfectant and pH levels
- Properly managing and disposing of backwash water
- Ensuring pool operators or technical staff are properly trained and qualified
- Carrying out regular water testing and record-keeping
Why choose Chemsol Group
Trusted by councils, leisure centres, hotels, and private pools across the UK, we offer expert support with pool filtration system design, installation, and maintenance.
You can also rest assured that our work is fully compliant with SPATA, BISHTA, and PWTAG guidelines and delivered by a team with more than 22 years of invaluable experience in this industry.
Arrange a consultation today!
Starting from scratch or looking to upgrade your existing pool filtration system? We provide a complete, turnkey service for deep bed filtration system installation with AFM®.
From an initial consultation and system design to installation, commissioning, and ongoing maintenance, we can help drive user satisfaction, maintain regulatory compliance, and protect the reputation of your commercial pool.
Whether you manage a leisure centre, hotel, spa, or aquatic facility, our deep bed filtration systems, combined with the advanced properties of AFM® are designed to enhance filtration efficiency, reduce chemical demand, and prevent bacterial growth.
The result is a protected investment in the form of healthier water and a superior swimming experience.
To arrange an initial survey or request a tailored quote for a custom AFM® deep bed filtration system, talk to our team.