Originally Posted by CrypticLifeStyle
anaerobic problems. It needs a richer source of oxygen which it's not going to get inside the tank or in the substrate. Yeah matrix is pumice stone. Old volcanic rock.
Thanks - I'll stick to putting it behind my Mattenfilters.
Any opinions on what is better - pumice stone or lava rock? I would think the lava rock, having larger "pores", would collect mulm & detritus more easily. But lava rock leaches iron (desirable to me) into the water as I understand it, so I would still use it to tie my anubias and java ferns to (or perhaps it contains iron that the roots can access - I can't remember).
So I will put pumice stone in the filters, and lava rock attached to water column feeding plants. Sounds good?