Here's a post I put up a while ago that supports Answer's reply. I doubt I'll ever buy a 1000, I'm planning to buy a new 600 soon.Hey Labrat, I can tell you after doing extensive research on HID's, that contrary to the belief that bigger is better, most now agree that multiple lower watt HID's are better than a single 1000W. This is for several different reasons.
These conclusions are what brought me to my purchase of a 600W HPS. They are supposed to be the most effecient. Having the MH through flower is fine and alot of people reccomend the mixed spectrum. The increased blue light during flower aids in trich development from what I have read. I am assuming that option E was for your warehouse grow?
- With more fixtures you can move lights and evenly distribute light better
- With the lower watt(400, 600W), you can place closer to the canopy so there is alot less lumen loss
- With the multiple lights you can add them as needed therefore not wasting energy
Cervantes did a real nice write up about this in his bible. Chapter nine, Light, Lamps, and Electricity. He outlined the parameters for consideration of lights, placement and wattage.
A 1000w HPS will put out ~140,000 lumens at 1' away
A 1000w HPS will put out ~35,000 lumens at 2' away
A 600w HPS will put out ~90,000 lumens at 1' away
A 600w HPS will put out ~22,500 lumens at 2' away
A 400w HPS will put out ~50,000 lumens at 1' away
A 400w HPS will put out ~12,500 lumens at 1' away
But you can't put them all the same distance away, the 1000w is much hotter than the 400w. And what we are dealing with when considering distance is the inverse square law. This law affirms that the intensity of light changes in inverse proportion to the square of the distance.
Here's the punch line.
We have to keep:
1000w HPS; ~3' above the tops, at 3' the 1000w put out 15,555 lumens.
600w HPS; ~2' above the tops, at 2' the 600w put out 22,500 lumens.
400w HPS; ~1' above the tops, at 1' the 400w put out 50,000 lumens.
Light intensity virtually doubles for every 6" closer an HID is to the canopy of a garden. I've singed a top twice by keeping my lamp real close, more like 6"-8" with the MH which is hotter than the HPS, I think this is a good strategy seeing as the plants have never seemed to mind getting a little hot, never hurt growth any. I always raise the light, but I never raise it more than 10" above the canopy.
Now the 400w can't cover the area the 1000w can, but for my money I'll buy the 400w and put more of them around for more, closer lighting and getting more lumens on those solar receptors we're feeding so diligently.
Plus when you consider the costs involved, I'm paying about $30/mo. for electric, that would be $75 for the 1000w. I just move them closer, sounds like a pretty easy way to save a few bucks, and be more energy efficient at the same time. Sure your 1000w is bigger than mine, but my sweetie is going to like mine better when I can buy her that fancy dinner!
I've got to give Cervantes credit for most the prior information. He's been incredibly thorough.