I have 4 plants. Temps are at 78. Bulbs are in air cooled hoods. No bleaching issues. I get a lb or more per plant. I've run 2 600's but I get way better results with 2 1000's. I don't see how it's over kill. Ideally you'd want 1000W per plant. My plants aren't small. I veg and train them for 7-8 weeks.