I appreciate your responses. Perhaps I should have mentioned that the veg room is7×8×8 and the 1000w mh is about 30" above the canopy. The bloom area is a 3×3×6 tent and the 400w hps will be approximately 14" above. I realize that this is slightly below the standard 50wpsqf but if I bump up to 600w I'll have to move the lighter further from the canopy as well as contend with excess heat issues. Should I still go for it?
Depends if they are LED or not. I went with LED for a couple of reasons: a. size of grow; b. heat; and power consumption.Unless you have multiple 400w flowering areas, you would do better to switch your veg to the 400w and flower under the 1000w. With a 7x8x8, you have enough space for 2 1k lights.
600w is too much light for my liking in a 3x3.