I used to keep snails with reptile dirt in my fish tank. Does any of those contain copper because im changing it into a salt water tank and copper is bad.
I doubt it contains copper if your snails lived for awhile because copper is toxic to snails and they would have died had there been any copper present.
It could possibly, what is the brand of "Reptile Dirt"? A fast way to find out is to google the company and find their phone number and talk to them directly, it may not say on the packaging but they will tell you personally if you ask them.
