Please Help - Grow Room Design and Light Choices

I'm preparing a grow room that I'd like to divide in half. The bottom half would be for mothers and clones with florescent lighting (T5's). The top half would be for vegging/flowering with HID lighting (MH for vegging, and HPS for flowering).

OK, so the room is 3.5' x 3.5' x 8'. Cutting it in half would make each half 3.5' x 3.5' x 4'. My grow tray is only 3' x 3'.

Questions

1. Should I base my HID bulb wattage choices on 3.5' x 3.5' (entire room size) or 3' x 3' (actual grow area)?

2. Would a 400 watt MH and 430 watt HPS work fine for me, or should I move up to a 600 watt HPS bulb? Heat is a concern for me with the 600 watt bulbs, but I can make it work heat-wise if it's the wattage I need.

3. How can I keep florescent light from the bottom half (mothers and clones) from interfering with the upper half (flowering plants) without also restricting air circulation from bottom to top?

Thanks.

Questions

1. Should I base my HID bulb wattage choices on 3.5' x 3.5' (entire room size) or 3' x 3' (actual grow area)?
Your canopy will spread out beyond your "grow area" and fill the entire 3.5' x 3.5' space, use that as your guideline.

2. Would a 400 watt MH and 430 watt HPS work fine for me, or should I move up to a 600 watt HPS bulb? Heat is a concern for me with the 600 watt bulbs, but I can make it work heat-wise if it's the wattage I need.
That one's a little tougher to answer! A 400/430 watter would probably work - but you might be "Pushing it!". A 600 watter might be a little more than you actually need - but you'll never be sorry! It's a matter of settleing for "just barely enough", or "plenty of power for dense nugs"!

3. How can I keep florescent light from the bottom half (mothers and clones) from interfering with the upper half (flowering plants) without also restricting air circulation from bottom to top?
There are several types of "light traps", surf through the Do It Yourself subforum. You will have the same problem at the exhaust port (except that exterior light will be leaking in onto your flowering plants! Light traps aren't that big of a deal to make and they work!

yes, light traps are extremely simple, useful, and cheap...