GreshamH said:
Finding food grade is just as easy IME so IMO I'd never risk it.
Unfortunately, that has not been the case for me. It took me 2 months of looking to find the first set of barrels I bought, and that's why I ended up going with soap barrels.
Recently, when I was looking for another barrel with the top intact, since I skillsawed the tops off of my old ones to make them easier to cure rock in, I even asked around at LFS's, talked to a few club members, called several soft drink distributors(who told me that if I didn't have a commercial account to go F myself and hung up on me, nice guys), and tried 3 different car detailing shops. I came up empty handed, so I ended up using an old aquarium I had around for my ATO, which works better anyways now that it's all set up.
Maybe I'm just bad at finding food grade barrels that someone doesn't want upwards of $80 for, but I went the route I did out of neccesity.
Also, FWIW, I won't ever fault you for being careful with your tank.