I'm running a single 400w with top drip recirculation and 25gal res using GH flora series. I just started week 4 yesterday 5/1/13 and went from 3tsp/gal grow 2tsp/gal micro 1tsp/gal bloom to 2-2-2 for trasistion to bloom. I need to know if I need to change the light to the hps and 12-12 now as well or do I wait until the next water change? Also once I do switch to 12-12 and hps do I change the watering timer too? Right now I have it set for 20min every 2hrs from 6am to 12 midnight. All help is greatly appreciated.