We bought a used aquarium, and it came with a ton of gravel, that would be perfect to use in the tank. However, my husband is afraid to use it, b/c we don't know if the previous inhabitants had any diseases. The tank hasn't been used in months according to the previous owners. I thought if the gravel had been sitting dry for months, any bacteria would be dead. What do y'all think? Or is there a good way to clean gravel to ensure it's safe. Boil it, maybe? Thanks!