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Led Grow Lights – The Importance Of Spectrum

LED Grow Lights – Confused Anyone?

In the world of LED Grow Lights the products vary dramatically from one company to the next, as does the information behind those products. I’ve often found myself confused at times by the contradicting information I find on many sites, which has lead me to do my own research as many often do. After all, with all the tri-band, quad-band, 6-band, 11-band, 12-band, and 15-band lights on that market, how do you know which one to choose?

HID Grow Lights – Why they’re being Replaced

Most of us switching to LED Grow Lights have used an alternative form of indoor lighting in the past such as High Pressure Sodium (HPS), Metal Halide (MH), or High output Fluorescent (T5). Any of us who have used these lights know one important thing about them: they are limited by their spectrum. The majority of the light a HPS or MH bulb emits is in the 500-600nm range, much of which is inefficiently absorbed by plants. In fact up to 70% of the light a HID bulb creates can be completely wasted in a grow room. Why is this you might ask? It’s because plants absorb primarily red and blue light, and need a special balancing of the light in those regions in order to grow optimally. HID lights are weak on both red and blue output, even though HPS is stronger in red while MH is strong in blue.
In the past when using HID you would want to utilize the spectral differences of the MH and HPS bulbs to your advantage, relying on the heavier blue output of the metal halide bulb in vegetative stage to keep plants short, and the HPS in bloom to allow them to stretch. The reality however, is that plants need a balanced amount of both red and blue in both stages of growth in order to grow optimally. Limiting either of these wavelengths creates a stress response in the plant to either grow shorter, or stretch, but when they are balanced properly you get super tight internodal spacing in veg with monstrous flowers during bloom. That’s what’s so great about LED Grow Lights, in that you can use one single light source throughout the entire growth cycle. Many people are still under the impression however, that you need separate vegetative and bloom stage LED Grow Lights when this is simply not the case.

The Science that drives Plant Growth

The main ingredients for photosynthesis are light, carbon dioxide and water. Just as our bodies require certain amounts of nutrients for proper cell division, plants require specific ratios of light for photosynthesis. Plants convert light energy into plant energy in their chloroplasts (much like the mitochondria in human cells). The chloroplasts produce Chlorophyll A and B, the two primary compounds that drive photosynthesis. These compounds absorb primarily blue and red light, more specifically, 439nm and 469nm blue, and 642nm and 667nm red. LED’s give us the ability to target narrow wavelengths of light so they can be specificaly tailored to provide the proper”light” recipe for photosynthesis. So based on this information on Photosynthesis, a LED Grow Light needs 4 wavelengths to target each of the chlorophyll absorption peaks.

In my reading I learned that Photosynthesis is not the only process that affects growth rate and yield. In fact there are two other important sciences that can enhance yield dramtically if they are applied to a grow light. One is called the Emerson Enhancement effect which dictates that when 740nm far-red light is shone simultaneously 660nm, photosynthetic rates increase as much as 30%. The other is called quantum efficiency which focuses on the importance of balancing each of the 3 regions of PAR, specifically focusing on green. It’s been learned in recent years that green actually plays a vital role on plant development, fruit ripening, and overall growth times, and that green penetrates deeper into plant tissues acting as a delivery agent for other wavelengths, as well as stimulating the lower chloroplasts. Studies by Nasa confirm that when green us balanced in with the green and blue wavelengths in the proper ratios, that growth times can be reduced up to 30% with a 30% enhancement in yield! The most familiar green for LED’s is 525nm, which means in total I count 6 wavelengths that are essential for optimal growth. 4 stimulate photosynthesis, 1 stimulates the Emerson Enhancement Effect, and the last fulfills the quantum efficiency requirements for faster growth rates and bigger yields.

LED Grow Lights – What have we Learned?

What we learned from HID lights is their weakness is producing a bunch of unused or wasted light. The strength of LED Grow Lights is being able to focus on the 6 wavelengths we discussed above, so that no light is wasted during the growth process. So what does that mean for all of these 11-band and 12-band or 15-band LED Grow lights? Quite simply it means that just like HID grow lights, they’re producing a spectrum where much of the light is being wasted instead of absorbed by plants. Likewise what does it mean for the tri-band or quad-band lights? It means they’re not developed enough yet to provide the types of results you need to outperform HID. Too little spectrum is just as bad as too much, and with the cost of LED Grow Lights you certainly don’t want to choose wrong or you’ll wind up paying a lot for it in the end. The Goldilocks zone are those 6-wavelengths you really want to look for: 439nm, 469nm, 525nm, 642nm, 667nm, and 740nm.

Penetrator LED Grow Lights – The Goldilocks Zone

The closest LED Grow Light I have found that fulfills all of the scientific requirements I’ve researched, are the Penetrator LED Grow Lights from Hydro Grow LED. These lights use a 6-band spectrum with 440nm, 470nm, 525nm, 640nm, 660nm, and 740nm. They really seem to have a grasp on LED Technology, and provide a lot of great information on their site. In fact they had a few extra articles on green and quantum efficiency that I’d never seen before, which taught me even more than I know now. They truly appear to be a pioneer in their field, and that’s why of any LED Grow Light on the market I would recommend theirs. Their 6-band spectrum is the real deal.