well not quite the same 1Ib per gallon = 2Ibs per 2gallons not 2.2 Ibs per gallon :)
Anyway I did mean 1Ibs per gallon, I was basing this on the rule I have heard many times which suggests 1.5 - 2 Ibs per gallon. Sorry I started waffling and couldn't stop :)
Just elaborating a little on the...