Cubic footage is what you want to think about for cooling and ventilation issues. For lightsâ??it's strictly ground area, so...square feet.

You've got 19.5 square feet of floor space. And you need more than 2000 lumens per square foot...much more. Like twice as much. Really, 5000 lumens a square foot is what you want to shoot for. So, for that area...19.5 x 5000 = 95000 lumens of light. You could do a good job with a 600w setup, especially if you've got secondary lights on the walls.

You have it rightâ??MH for veg, HPS for flower. My suggestion would be either a 600w or 1000w switchable ballast set up. You can pick one up for under $300, complete with ballast, reflector, an MH bulb, and an HPS bulb. A 600w MH bulb gives you about 60000 lumens, which isn't enough to cover you whole 19-20 sq ft. area. ON the other hand, you need more light in flowerâ??and plants are (a lot) smaller in veg. The 600w HPS will put out 85000 to 95000 lumens...even without the secondary lights, that would be enough to do a great job. A 1000w setup would up those number by another 50% plus.