You can get Hatchrite from kingsnake.com usually, I haven't used it yet but I heard it's foolproof and am looking foward to needing some in a couple of months =). Being as last time I was in Philly I didn't see too many farms lol so I would probably not go crazy looking for Vermiculite there. But if you really want it try looking online for aggriculture supply places they will have it for sure.