I'm looking to get a storage container for my fish room and it seems like rain barrels are significantly easier to find around my area than those standard food grade 55G barrels. However, I'm not sure if rain barrels are safe to use. Here's the one I'm thinking of getting:
It's easily found at my local Home Depot and I like the overflow feature so that I can walk away when filling it and not have to worry about flooding my fish room (the overflow hose would be run to a drain). The specs say it's made from high pressure injected high density polyethylene resin.