Yeah, I don't know of where you would find them at brick and mortar, maybe a store that sells home brewing or home wine making supplies, maybe a store that sells hydroponic gardening supplies (yes they exist around ATL anyway).
Really though, it's pretty readily available online. I'll second Reptile Basics, if you're on the east coast they're the best bet, and the shipping is rather quick. On the west coast I would recommend the Bean Farm.