This is the AFM GRADE 3 (support layer) which is usually used by pool owners in large sand filters, 36" or greater, as the first part of the 3-Stage Activated Glass Filter System, in lieu of pea gravel. It supports the laterals inside the sand filter body and under grade 2 and grade 1 media.
ZeroChlor recommends AFM Filters anytime a pool is upgraded to the ZeroChlor Pool System. Consider adding on AFM during checkout! If it's not AFM it'snot Activated. Activation of the glass media is the most important part!
AFM is an Activated Filter Media, manufactured and activated by Dryden Aqua under ISO procedures.
AFM is manufactured from reprocessed glass, but it isnot a basic crushed glass filter media. We have experience with lots of glass media brands but none of the brands we have tried even come close to the performance and longevity of AFM. AFM is ahighly processed productthat has been tested by independent UK Government laboratories and the water industry and has been certified safe for all water filtration applications. Filter sand has bypassed the regulations because it was in use before the regulations were in place. However, man-made filtration products are not exempt, and AFM is the only filtration media that is in compliance with the regulations and is safe to use for applications such as drinking water, swimming pools, and aquaria. A basic crushed glass product does not have surface-active properties, there will be a hydraulic lens effect which leads to channeling, there are also serious health implications for the public and contractors from using a basic crushed glass product. Dryden Aqua has completed a 1.2 million Euro Research Project in co-operation with the European Commission under the Life Environment initiative to solve these problems. For information www.drydenaqua.com/afm