Planted Tank Obsessed
Join Date: Dec 2014
Location: Colorado Springs
Nylon pot scrubbers, for example, are dirt cheap and offer crazy amounts of space to colonize if you're looking for cheap, DIY filtration media.
As near as I can figure, the marbles would be 99% solid glass, with a slight colonization of the scratched up surface. Has anyone tested out what this actually allows for bio filtration in comparison to a similar sized sponge layer for example? (I would presume even a coarse, rinseable sponge would offer significantly more bio colonization than the marbles, cost less, not require sanding, and it's easy to rinse/re-use, and works as mechanical filtration on top of that)
I guess I'm missing why marbles.
(although I am looking to use marbles for some valves I want to design, I don't think they're well suited for filtration media)