CFL Grow, quick question

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LoganLikesSchool

New Member
Hi everyone! Quick question here.

I'm sure this has been asked 1,000,000 times but what is the best Wattage for a PC sized grow box?
I have seen mixed reviews after scrolling through various posts here on the forum. Some people swear by 23w 5500k bulbs (using 3-4 of them), or some people stating that they believe 100w Bulbs are better (1 or 2 of them). To my understanding, giving the plants a larger amount of wattage with a wide range of spectrum would be best (5000k or higher, at least for Veg. And lower for Flower). Any ideas here? I have the option to use 4x 23-30w 5500k bulbs, or 2x 65w+ bulbs. any suggestions, comments or concerns? Thanks :D

Edit: Growbox is 30" tall, 20" wide, 20" deep

-Logan
 
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W

WeedBulbs

Member
It was a quick question, but not a quick answer... but one that I needed to be able to answer... so thanks!

According to http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3550641/pdf/12298_2008_Article_27.pdf, you need 500 umol/s per square meter for best and most
efficient growth. For a 20in x 20in grow space with reasonably reflective walls, this equates to 135 umol/s Photosynthetic Photon Flux.

I had some generic 26 watt CFL "Grow Light" tested and have attached the color percentages. This is important because any green over about 24% is ignored by plants (this
is why plants are green). I am assuming that your generic CFL has roughly the same percentages. So after reducing the watts to 23 and ignoring any green over 24%, the 23 watt generic CFL outputs about 13.9 Effective Photosynthetic Photon Flux.

To get get up to the standards recommended in the research quoted above, you will need about 10 of the 23 watt generic CFL.

So if you continue to use generic CFL, you will need about 230 watts total for your PC grow box.

In a couple of months, we will be launching a targeted spectrum 24 watt CFL that has 21.72 Effective Photosynthetic Photon Flux. It will take 7 of these bulbs in your PC to give you the needed light for a total of 168 watts. When we launch, I will be giving people in this forum a 90% off coupon in return for an honest review.
 

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