Reflector Positioning

Hey, if my grow area is a rectangle, should I have the long side of my reflector lined up with the long side of the grow area or the short side of the grow area? I'm thinking the long side of the reflector should go with the short side of the grow area, but I just wanna double check.

Also, I'm using a 400w MH for veg, do you think that is adequate for a 36"x24" grow space?

Thank you.

Long side to long side. Looking at the long side of the lamp, the bulb has a wider unobstructed area from left to right.

Mother's Finest said:

Long side to long side. Looking at the long side of the lamp, the bulb has a wider unobstructed area from left to right.

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makes sense to me............your space is 3ft by 2 feet?? a 400w should cover that well...400w = 3x3 so you should have more light then you really need actually.....and when i say more then you need well you need it so dont get me wrong here....lol

Well if you say it covers 3x3 does that mean that both long side and short side of the bulb cover a 3ft distance so it doesn't matter which one is which way?

It's the lamp housing that is often rectangular and affects the size and shape of the light's focus area. With an MH, much more so than even an HPS, the arc tube inside isn't very long. This is the part of the bulb that the light comes from so even though the bulb may be longer than it is wide, the light more or less comes from a point.

If you have a "good" reflector, I would count from the middle of the reflector, and out, in both directions (3x3 for 400w, 4x4 for 600W, etc). The reflective material is "suppose" to evenly distribute the light.