Alternative media: cellulose and recycled glass show promise as green-friendly alternative filter mediums. Here's the lowdown on each.(TECH TALK)

Two new filter media are available that show promise in reducing costs and environmental impact.

The first is called cellulose. Chew on a piece of wood and it will break down into a mass of fibrous material. This jumble of fibers is cellulose, a carbohydrate made from glucose, which is a form of sugar. Paper is made from cellulose. Filters made from cellulose paper have been in use hundreds of years. Now there's a cellulose media that can be used in an aquatic applicaton as a replacement for diatomaceous earth, which can be an environmental hazard.

You see, DE is composed of tiny exoskeletons left by sea creatures called diatoms. The collection of skeletons contains a microscopic labyrinth that results in excellent particle filtration.

However, those same properties can be dangerous to humans. Indeed, the Environmental Protection Agency considers DE a carcinogen and recommends wearing breathing protection when handling it. Also, California now requires that DE be disposed of at hazardous material landfills.

In contrast cellulose is non-toxic and biodegradable when be thrown out with the garbage or disposed of through the sewage treatment plant.

One new product has even gained National Sanitation Foundation approval, thanks to a test that put the cellulose media in head-to-head testing against various DE media. The results of these tests (NSF Job PSF J-00014263) show that the cellulose media performed as good or better than DE in terms of filtration and pressure drop performance. If the tests prove true, cellulose is capable of higher dirt loading, which means longer periods between required filter reconditioning, less expense for new media and less time to recharge.

Just keep in mind that each cellulose brand is different when it comes to fiber size and treatment. To prove they are capable of meeting NSF requirements, all brands should submit to the same qualifying tests. In time, I am sure that there will be other brands of cellulose with the NSF label. The good news is that the "jury is in" and cellulose is a bona fide DE substitute.