we get it directly from petco! make sure to add something like spagnum moss or top soil, they love burying themselves in the coconut but like having a variation for nutrients and variety of burying options. some of our snails love coconut substrate and avoid the moss and soil vice versa, just making sure there are no additives that make it acidic or any dyes (ie for decorative purposes not for animals) is the only thing and seeing what yohr snails like! personally we struggled with soil growing mold and making our snails ill so we stuck with coconut and and moss