Are there any benefits to oversizing an LED grow light.

[Frankster]

Lights are always a controversial subject, we've all got idea's of what works best and want to defend our positions.

At the end of the day, there's more than one way to skin a cat. I'm certainly not suggesting that all situations could benefit from what I'm suggesting. We've all got to look at the setups we have, and try to look at what's out there, and how things can be improved. Or even if they need improvement.

Sometimes keeping the status quo, is the best way forward.

I know plenty of phenomenal growers who still use old school HPS and don't plan on ever switching over. There's certainly advantage to every situation, cause HPS also generate a great deal of heat energy during the winter months, which is needed sometimes.

It's a mixed bag, is what I'm saying, so people have to make choices for themselves, and utilize what works for them.
That said, generally speaking if you've got more light sources, and closer up, it's going to help improve overall efficiency. But the how in all of this, is the part that needs to be studied in each situation.

 

[growsince79]

The problem with figuring out the math's

Yea, certainly with overpowered light, your correct. But my point being, a single source of light, vs an array of lights; and array is always going to beat a single light source, cause you can move it up, and your getting overshadows from multiple different angles, and overlap, this creates far superior penetration of the canopy.

Resulting in overall thicker buds, and lower stuff that's not larf filled, creating more uniformity downwards.

I seem to remember this argument in the 70s. Then it was vho florescent verses mh. People decided MH and single source bright lights were better than spread out. They also decided intensity trumps spectrum- hello hps goodby growlux vhos.
In terms of efficiency, today's leds are way more efficient than vho, MH or HPS. But when efficiency doesn't matter, the further away the light- the better the distribution. Kinda like the sun. A 1000w MH 5' above a 3 x 3 will be as uniform as it gets. Not sure I agree with 5 x400w outperforming 2 x 1000w hps- I'd like to see the side by side.

 

[Frankster]

I seem to remember this argument in the 70s. Then it was vho florescent verses mh. People decided MH and single source bright lights were better than spread out. They also decided intensity trumps spectrum- hello hps goodby growlux vhos.
In terms of efficiency, today's leds are way more efficient than vho, MH or HPS. But when efficiency doesn't matter, the further away the light- the better the distribution. Kinda like the sun. A 1000w MH 5' above a 3 x 3 will be as uniform as it gets. Not sure I agree with 5 x400w outperforming 2 x 1000w hps- I'd like to see the side by side.

Yea, I wish I had the data to back it up. But I'll concede this is a well hashed argument.

 

[growsince79]

Yea, I wish I had the data to back it up. But I'll concede this is a well hashed argument.

You should start a thread on diffused light verses direct light. The studies I've seen suggest that a combination of both is the best mix. I think that would be a great thread we can all learn from.

 

[Frankster]

UVB gets into areas that can harm your skin. UVC is where it gets really dangerous to both human flesh and plant flesh. UVA is harmless ... and is what you find on many 660nm + UV + IR setups. If you're looking to bring out terps, look for lighting that has around 310nm wavelength.

This is what I've read on this subject. Ultraviolet (UV) light is a natural part of Sunlight that reaches the earth, and is invisible to the naked eye. At ground level, sunlight is approximately 3% UV light.

The wavelength of visible light ranges from 400-700 nanometers (nm), a nanometer is a billionth of a meter. Light waves ranging from 10-400 nm are known as UV light. The Sun is a source of UV light, which is commonly subdivided into UV-A, UV-B and UV-C light. UV-C light is almost entirely absorbed by the atmosphere surrounding the earth. UV-A light measures between 400-320nm, UV-B is between 320-290 and from 290-100nm is UV-C.

UV light is measured in micro-watts per square centimeter (µW/cm²) “µ” is the symbol for “micro-watt” UV-B occurs naturally in sunlight. Much of the UV-B light produced by the sun is absorbed by the Earth’s ozone layer. However, depending on your location on the globe, the season of the year, and the time of the day UV-B levels can be upwards of 400 µW/cm².

UV-B light is required to allow skin to manufacture Vitamin-D. When exposed to adequate levels of UV-A and UV-B light, the amount of the brown skin pigment, melanin, will increase, commonly known as a sun-tan, and over exposure will cause a sun-burn. Humans are able to regulate their UV-B exposure by either staying out of the sun, wearing sun blocking clothing, or using chemical sun-block creams.

Less is known regarding Plant reactions to natural levels of UV-B light. Unlike Humans, Plants are unable to avoid UV-B light, nor are they able to apply suntan lotion. It is widely accepted that when plants are subject to UV-B light, this event triggers the plant’s defense mechanisms. It is exactly this defense reaction which is targeted by many users of the Pure UV lamp. In many plant species, exposure to UV-B light will cause changes in phenolic compounds, flavonoid pigments, resins, oils, etc. It is this ability to enhance plant growth, naturally – without the use of chemicals that the

AgroMax Pure UV lamps provide 75% UV-B, 25% UV-A and a very slight amount of visible light are up to 15 times more powerful than specialty “reptile” UV lamps.


I'll have to say, I notice a difference, although I only run 1 (55w) light in my 4x4. I have a second unit, but not currently using it. They say it increases resin production up to 28%, I don't know about all that, but it certainly has increase it some, and it's also helped improve flavors, and cut down on PM issues. I like the pure UV t5's, I think they were a worthwhile effort.

So much of the grow parameter IMO revolves around the spectrums itself. Not intensity, but the ratio of light spectrum itself.

Frontiers | Beyond Arabidopsis: Differential UV-B Response Mediated by UVR8 in Diverse Species

Ultraviolet-B radiation (UV-B, 280–315 nm) is an important environmental signal that regulates growth and development in plants. Two dose-dependent UV-B resp...

www.frontiersin.org

Sensing of UV-B radiation by plants

Daylight UV-B (UV-B) radiation (280–315 nm) is, because of its photochemical effects and potential destructive impact, an important environmental factor for plants. After decades of fruitless attempts, a receptor molecule, UVR8, for sensing of ...

www.ncbi.nlm.nih.gov

 

[Frankster]

You should start a thread on diffused light verses direct light. The studies I've seen suggest that a combination of both is the best mix. I think that would be a great thread we can all learn from.

There's little doubt that that's a real thing. I just think it's such a hard subject to grab hold of and actually pull something out of it. I'm really with you on this one, cause it seems some of the best strains IMO, are grown around that 45 degree latitude in Marine environments. A little above, a little below, but as you creep up the coastline it gets a tremendous amount of this type of light during the flowering months.

I think it's a huge component of quality sunlight in the outdoor grow parameter.
Indica's clearly evolved in climates zones such as this.

 

[growsince79]

There's little doubt that that's a real thing. I just think it's such a hard subject to grab hold of and actually pull something out of it. I'm really with you on this one, cause it seems some of the best strains IMO, are grown around that 45 degree latitude in Marine environments. A little above, a little below, but as you creep up the coastline it gets a tremendous amount of this type of light during the flowering months.

I think it's a huge component of quality sunlight in the outdoor grow parameter.
Indica's clearly evolved in climates zones such as this.

The best sativas developed in places where they get sun and clouds and rain almost daily. My personal studies mixing confirms for me at least - partly cloudy hps/led mix for the win.