Damn man that is a "expert" growers mark...1 gpw. Good luck to you with that. I barely average .75 per watt using HPS. I know for a fact though if I was to switch to sythetic nutes and/ or hydro I could attain 1 gpw. But in the end I care about my quality rather then my yield. As long as that isnt damaged I am golden.
Curious, how do y cool them? I know they don't put off a lot of heat ( i use them for mother and veg) but with an abundance if them like you have it has to get hot, right?