I'd just be very careful and observant of the fish once you put the mossball even after you wash it. Because if it's a parasite like ich or velevt, I wouldn't be surprised if they found a way to survive on a mossball until they find a new host. Unlike fake decor, live plants cannot be sterilized as harshly. I'm not a scientist either so maybe I'm wrong but I'd still be careful regarding reusing anything live that was in a tank with a fish that died of a parasite. If it was incorrect water parameters or factors like that, then I wouldn't worry because it's not something that's living. Anyways if you catch any signs of velvet or ich, then treat it asap because fish can survive it, it just needs to be treated in the early stages BEFORE it progresses.Zofia said:So I have a moss ball that was in a tank I had a Betta that died. I'm not sure of the cause of death, I'm thinking he died of ich or velvet . Regardless, can the moss ball be reused? I, of course, will do a 100% water change and thoroughly rinse the substrate and everything that was in the tank.