You haven't got a hydro shop locally? Sometimes even Home Depot has some interesting products on the shelf. They've been making a push into carrying "cultivation" products lately. I'm not in a legal state and I've been quite surprised by what they had lying about. It's the sort of thing you wouldn't notice if you didn't know/need it.
EDIT: The local Depot here with a large outdoor garden area recently had : Bricks of coco, jobes fertilizers, Earth Juice products, Osmotcote fertilizers in specified Veg and Bloom forumulas, etc... might be worth a trip to their garden section if you're in a bind and see what's there.