Biomedia Poll

[Ken69]

Wet/Dry - Bioballs or similar. Wet sump or canister - Seachem Matrix or Pond Matrix (Pond matrix is just a larger size), or Eheim substrat.

Cheers,
Ken.

 

[Toby_H]

I marked other...

Bacteria will grow on essentially any/every surface in a tank/system... So I use driftwood, rock, sand and mechanical filter media (mostly sponges of some sort).