Every aquarist needs to think about bacteria. Aquarium cycling is when fish tank bacteria grow to consume fish waste and convert ammonia -> nitrite -> nitrate -> nitrogen gas. During and after the aquarium cycle, bacteria need biological media to live on. With proper maintenance and beneficial bacteria, aquarium nitrate levels will remain low. Bioballs and ceramic rings are two basic biofilter choices. Many hobbyists use highly porous ceramic plates or bricks housed in the sump. Bio pellets are a plastic media that house and feed bacteria. Zeovit is part of a specialized system to maintain ultra low nutrients.
Biological Media
Filters
$11.89
From $12.77
AquaMaxx
Biopellets - AquaMaxxFrom $29.99
From $28.89
$51.84
Seachem
Seachem Laboratories MatrixFrom $11.55
$28.04
Brightwell Aquatics
Brightwell Aquatics Xport BIOFrom $40.95
Brightwell Aquatics
Brightwell Aquatics Xport NO3 - Dimpled Brick$43.65
From $25.99
From $11.55
From $10.49
Warner Marine Research
Warner Marine ecoBAK Plus BioPellet Filter MediaFrom $24.99
Lifegard Aquatics
Lifegard Aquatics Bio-mate BioballsFrom $11.99
From $9.99
Warner Marine Research
Warner Marine ecoBAK BioPellet Filter MediaFrom $19.99
Brightwell Aquatics
Xport BIO Cubes - Biological Filtration Media - Brightwell AquaticsFrom $9.99
$13.99
$20.99
From $28.99
$15.99
$14.99
Lifegard Aquatics
Lifegard Aquatics Bio-Mate, 1-1/2 inch Carbon Filled Balls, 1 Gallon$20.19