Reusing 'old' gravel
A friend a few months ago unfortunately had his tank crack and leak. He moved over the fish into a secondary tank. He drained the aquarium and left the gravel in the broken tank. It is expensive gravel - it's dried up now and he offered it to me.
Question is, would it be safe to use after I rinse it? Just worried of any weird things that might have developed in it. Mold, fungus if that's even at all possible.