Media Darlings for Biofiltration
Learn how filtration media affect a biological filtration system's effectiveness.

From Water Garden News

www.watergardennews.com

By Devon McPhee
Part of a biological filtration system's effectiveness depends on the type of filtration media used. Filtration media provides a place for beneficial bacteria to grow.

When comparing filtration media, consumers must pay attention to surface area, said  Hung Hoang, president of SeaGate Filters in Alexandria, Va. The more surface area, the more places for beneficial bacteria to grow, he said.

The most common biomedia include bioballs or tubular media, lava rock, filter mats and ribbon media. Filtration media range in price from $18 per cubic foot to $120 per cubic foot, based on surface area. Generally speaking, the more surface area, the higher the price.

Bioballs or tubular media offer a high surface area, making them a favorite of pressurized filter manufacturers. They also have developed ways to make maintaining them easy, said Bill Lane, marketing director for Savio Engineering Inc.

"Pressurized filter manufacturers have developed solutions incorporating internal jets and hand-operated agitators to make cleaning [bioballs] unintimidating and palatable to the general public," he said.

Lava rock appeals to pond owners who want eco-friendly options, Lane said. The high surface area comes with a downside though. "The small pores in lava rock get clogged -- it's no fun to clean and the cleaning process tends to kill the beneficial bacteria -- reducing filter effectiveness until bacterial colonies can grow back," he said.

Filter mats are one of the cheapest forms of biological filtration. As the name indicates, they're mats, usually placed behind the skimmer, on which beneficial bacteria grow.

The newest media out there is ribbon media, which has a high surface area and is easy to clean. Some manufactures impregnate their ribbon media products with elements that foster bacteria growth.

Choosing biomedia boils down to convenience and price, Hoang said. "Consumers who want to do little maintenance will pay more than consumers who are more concerned with price over convenience," he said.

Michigan-based freelance writer Devon McPhee's complete article, "Let Nature Do the Work," appeared in the August 2007 issue.