The problem is not the copper leeching into the water. The problem is the snail actually ingesting it. That's far more likely to do harm in my opinion. Copper sulfate is put in fish foods to stop fungus from forming on uneaten portions. It has no beneficial element for the fish or snail at all.Pringlethesnail said:I do use foods that have copper sulfate in them as one of the last ingredients on the list and I am careful that all the food is eaten within 2 hours so that the copper doesn’t leech into the water. The copper amino acid chelate is copper in the shape of an amino acid I believe. However, zinc is also toxic to snails. Less than copper, but still really up there. Considering that food has two forms of copper and two forms of zinc. I would not use it. Depending on water changes, filter output, and time uneaten food sat in the tank that food could kill a snail, but it also could’ve been old age. My favorite snail food is HikarI bottom feeder wafers. They come in an orange bag and I get them from amazon, but they have it in most pet stores near me (NY). The snails LOVE it and it’s soft and easily digestible for them. That’s the best thing I’ve tried so far. Look for anything with meats and make sure if there is copper it is way at the bottom of the list.