So the stuff I posted isn't any good?Most of the cannabis centric soil offered will last from 4 - 6 weeks with clear water feeds out of the bag. You should be able to veg your plant most of the way without having to supplement with fertilizer.
I use a pretty basic formula that isn't too costly and works well for me.
General Hydroponics FloraNova Grow
General Hydroponics FloraNova Bloom
Advanced Nutrients Cal/Mag w Iron
pH Up and Down
For less than $150 I can do 2 runs in the 5 x 5.