I´ve seen it and its a great tutorial on how to build a drip and a ebb and flow hydro systems, and how things work in the hydro world, but one thing left me O.o, i didn´t know there were HPS in blue spectrum....Mr Green keeps saying this through the entire clip..wich i bealive is not true...either u have MH in blue or HPS in Red/Orange spectrum....Peace and Pot