I use the Raw. It's three forms of sugar. Fructose, sucrose, and I forget the other one. It aids in the plants' metabolic process of breaking H20 through photosynthesis to create starches and metabolize nutrients.
I only use the Raw because I grow multiple strains. Sorry bro, I can not comment on the Grape or Citrus lines of Sweet. I don't want a lime strain tasting like grapes.
If you're running in a "soil less" mix...potting soil, molasses will do the same thing---feed your microbes; but on the cheap.
I just cracked a gallon of Sweet Raw. I like it. Works for me.