I've posted this elsewhere, but received no response. I was wanting to know if anyone buys carbon in bulk, and if aquarium grade carbon would suit my purpose. I think I won't have a problem building my own, and I'd really love to save the money, rather than fork over $350-550 on a scrubber/fan. Please advise, thank you. eBay: Ammo-Carb White Mixed Carbon Ammonia Remover 38lb Bulk! (item 280047106353 end time Apr-07-07 17:04:26 PDT)