Im really not sure how many ur going to need per plant but I do know tha tu should put the lighting between 1-3 inches away from plant..anything further away is useless........in regards to he hps you should be about 13-20 inches away ....remembering to alway monitoring youi heat.......im using a 400watt hps/mh and with 65 watt cfs ant thats how im using them..now i can keep thehps closer due tot eh temps in the basement ......it cold down in the room sometimes...smoke on..peace....