More Important for seedlings? Wavelength or intensity?

[BlueDevil]

What's the accepted view here among the experienced folk?


Could a 55,000lumen HPS be better for growing rather than with a 36,000lumen MH bulb due to it's difference in brightness, or does the blue-white spectrum of lighting (even at a lower intensity) simply account for too much of what the vegetative state needs?


Reason I ask is I have this choice to make and I've heard some people use HPS for the life of the plant. :confused:


All input appreciated!

[Splifted]

Well, from personal experience, I vegged under warm white cfls then flowered under an HPS, and it worked just fine. If you only have to pick one light, I'd go with the HPS. HPS works fine for veg (shit, mine grew like a weed under it), and it is by far the better spectrum for flowering, so if you only had one light to use for the whole process, you'd be better off with HPS.

We were just discussing something similar in this thread, scroll down to see the pics I posted a few posts down. http://boards.cannabis.com/showthread.php?t=95140

So, from experience, light intensity is more important than light spectrum. Go with the HPS, you will not be disappointed. The main difference is the blue spectrum causes slightly shorter, denser plants during the veg cycle than the red spectrum, but not to the point where its a big deal IMO.

[Flower Child]

Intensity is better... but the blue light sure stops the s t r e a c hing.
FC

[invision]

i have never had any stretch issues with my hps, id say the more light the better if you can only get HPS.

[lovetogrow]

if you can get only one then get the hps and buy the hps convertion bulb with it. that way you can run your hps bulb for flowering and use the convertion for veg, cuz lets face it switchable are to high priced. you can get the the convertion bulb for a 400w hps for $50 at http://www.discount-hydro.com/lightbulbs.asp



Sunmaster Conversion Bulbs are metal halide bulbs that operate on high pressure sodium ballasts. They are perfect for giving your plants the blue spectrum that they need for the best vegetative growth. These bulbs are available for 1000, 400 and 250 watt high pressure sodium ballasts. The 1000 and 400 watt put out a balanced 4000° K blue light. The 600 watt puts out a cool 6500° K blue light. They are universal burning bulbs which means that they can be used in any fixture, vertical or horizontal. These bulbs are environmentally friendly.