Green Vista Jumbo 1.5 Inch BIO Balls/BIOBALLS 300 Count Filter Media with Free Beneficial Bacteria Jump Start - Cleans Water in Ponds and Large Aquariums - Increases Dissolved Oxygen PROMOTE BENEFICIAL BACTERIA: Green Vista Jumbo 1.5 Inch Diameter Bio Balls / Bioballs Filter Media are 72 percent larger than the common 1.25 inch size. These Bioballs feature an extremely high surface area for beneficial bacteria to colonize. The trickle effect boosts dissolved oxygen levels in ponds, aquariums and other waterscapes. It also cleans or filters the water as the Bioballs combine with organic waste. WORK IN MULTIPLE WATERSCAPES: Lightweight, superior filtration media, Bioballs are effective in various water features. They are used in ponds, including koi ponds, aquariums, hatcheries, tropical fish farms, waste water systems, cooling towers and additional commercial and industrial systems. NEVER NEED REPLACEMENTS: Long lasting, Green Vista Bioballs do not have to be replaced! This package contains about 300 pieces of 1.5 inch diameter Bioballs. BETTER THAN LAVA ROCK: Bioballs are a far better option for bio media than lava rock. They also weigh much less than lava rock, making them easier to handle. INCLUDE FREE HELPFUL BACTERIA: These Bioballs come with Hydro-Bugs Beneficial Bacteria jump start for bio filters. The beneficial bacteria work with the Bioballs to filter and clean water features.