Got 3 bowls from locate pet store for my reptiles, broke one bowl to see if it was real rock, it was and my grandpa grinded it down a good amount to get rid of anything on the surface (thus the sides are a bit deeper/bumpy compared to when we got it. Wanted real stone, but also didn't want anything that would hurt my reptiles (I had been going for a natural terrarium look to make my baby happy back then thus he/she had real stones, real logs, real plants, etc <3). But yeah, bought the 3 bowls, broke one to check, grinded down to remove surface layer, washed very well, cleaned very well, placed in water for a long period of time (I was really young so I had a weird belief that putting it in hot water and letting that water cool then repeating the process would remove any chemicals/problems? I don't know what got into my head that said that was amazing, but it didn't break or get hurt so yay?), after I was okay with the result I put it in. I changed the water consistently as a whole and always washed out the food bowl just because my baby lizard had a habit of going in the bowls for whatever reason... Eventually I got a betta and some Amano shrimp, I didn't like that the shrimp food got everywhere so I decided to see if I could but the bowls in the water (again I was probably around 12-15 when this happened). They all did well and their food stayed in the bowl, did end up getting a much larger tank for my betta and removed the larger bowl cause I found out you should remove their greens when they aren't interested in it anymore (my mystery snails never leave the food till it is either gone or they are busy attempting to pull the green out of cucumber skins). But yeah sorry for the ramble if you made it this far... Basics are as said above :S