Adding nutrients and flavor

You cant "add" flavor , flavor is genetically depending on the terpines and flavonoids your strain produces , Depending on photoperiod or autoflower strain you can start feeding a little around week 2-3 with a grow fertilizer , use it sparingly , too much can make your plant look defficient because the roots are sitting in a too hot soil , my first grows i only used fertilizer when i needed it , you will have satisfieing results with just normal water always remember that less is more