You will be Very happy with the results if you do decide to run both bulbs. Currently i am running 1 -1000w HPS & 1 - 400w MH Bulbs under the same hood. All the Buds on top and sides are Extremely tight, and crystal covered. I can see a differance running the extra 400w MH. Last flower cycle i just used a 1000w Hps. With running the extra 400w Mh, the buds look and feel alot tighter. :hi