Porous structure, plastic biological filter media.
These are supplied in the Cf range of canister filters and are frequently lost over time. Also great for trickle filters and any large volume biological filters.
Extremely light weight in any volume
Massive void space so will not block
Use in the bottom of CF canister filters
Work very well as a general use biofilter media
We recommend only using Aqua One genuine spare parts in their range of filters