
Originally Posted by
mpmistr
Not sure why your amazon swords are rotting, really the sand itself would be inert so if you are using root feeding plants like swords or crypts you'll want to use root tabs (or dirt capped with sand) to keep these plants.
As far as black volcanic sand, I am not sure what brand you are using. In the US the main choices for black sand are Tahitian Moon (Caribsea), Black Diamond (coal slag), and I believe PetCo carries a black sand as well but I found it very similar to Tahition Moon, very jagged/sharp sand.
Your sand may be different, I know there is black sand in Hawaii and I've never really tested it to see how well it works in an aquarium (also it is illegal to take off the beach!).