I use "Bio-grow" from Worm's way. It is a molasses based organic product you use with every watering to soil grown plants that gives a constant low dose infusion of nitrogen. Good stuff and will not cause burn.
As far as flowering: "Bio-bloom" (also an organic molasses based product) is a constant low dose food that can be given with every watering that gives an infusion of "P" to stimilate flowering after you are the 12/12 cycle..