Filter Carbon Substrate
Hi all, I came across some small ~1mm "gravel" that I inherited and was gonna use it in my 5 gallon, but then realized "hey, this could be filter (activated) carbon!" Then I thought "wait a minute, plants use carbon!" then I thought "I wonder why this stuff isn't used as a substrate?". I realize that it's not pure carbon, but surely it contains some!?!
Anyone have any good reason NOT to throw this stuff into my 5 gallon (which only houses guppy fry atm)? Better yet, anyone ever use activated carbon in the substrate?