I Have a 400w mh about 18in away from top foilage. I just got them from a friend yesterday...not much info came with it beside its about 15 days off plant and yes the plant was just begining the flower stage..the guy I got it from says he used some sort of root gel compound and no clue the current median, been using pure water to feed and foilage spay......I have Some "Ocean Forest" foxfarm soil for when i transplant and i have "Big Bloom", "Big Grow", and "Tiger Bloom" for nuts when i transplant. Great 24/7 Air flow,intake ,exaust, and curculation fan. The PH of current median is 6.8ish (kinda shitty tester) median looks as if its a peatmoss,soil, and sand mix sorta...