Well my friend, as it turns out, the flip ready plants are pretty much plug and play for the first two weeks, then you have to go to work. If you really want to feed them, that is OK. I use Alaska Fish Fertilizer mixed with pH corrected water and I top dress with kelp meal and fresh compost. That is all.
After 12 days, these plants will be fully root bound. Best case scenario is new containers no less that 3 times larger. Otherwise, two of the very largest containers you can get together. Would suggest 6 or 7 gallon.
From there, you will need some soil. If you are going Roots, get the 707, the regular is too wimpy.
Same feeding for me until 1-2 weeks before harvest, and then only water.