I used the same exact nutes for awhile and I just followed the instructions on the back.

High Tech Garden Supply

the link above is what i bought as my first light, I searched around and found that to be a good deal. this way you get both lights. The qaulity of the product was fine. in fact I went on to purchase 2 1000w switchables from the same place. One had a malfunction in the wiring half way through my 12/12 cycle and after calling the store and explaing my situation this guy next day aired me a replacement at no charge and just asked me to return the piece that was broken and I could keep the extra parts, which included the 2 bulbs that came with it. I feel bad because I never sent that piece back and he shipped it out immediatly, so maybe if I refer you to him it will take away some of that bad karma................ wow i'm rambling. And he's aslo in PA so shipping would be dirt cheap.