Deniballs?

Question

I recently bought a nano cube that comes with deniballs can I put them in the spot in the back or do I need something else, if so what would be the best?

Answer 1

Deni balls are made of a special biologically based material and are designed to provide a long term carbon and food source for anaerobic bacteria within the nitrateredctors in absence of oxygen you need a Nitratereductor