Blue / Red light. Is red needed?

Growing peppers this winter and buying lights now. Need to know if I need red light.
My basic understanding is that peppers begin flowering after division which occurs based on nodal growth rather than light length. I know red light is important for 'other' plants to flower.
Can I grow my peppers solely under blue light? I would assume the red lights would just be a waste and the plants would grow faster under pure blue light. Unless there is a need for the red light I am unaware of?

Sorry for the stupid question. I guess this has probably been asked many times but there are hundreds of threads here about lighting and I can't pick through them all.

Thanks in advance.
Ugh, I don't know why my posts get compounded like that. I try to make good use of spacing for readability. Sorry guys.

no, red light is much more important than blue. If you want it to be simple just use white light. When you start controlling the spectrum closely with individual wavelengths it gets pretty complicated.
 
http://hortsci.ashspublications.org/content/48/8/988.abstract
 
http://aob.oxfordjournals.org/content/79/3/273.full.pdf

Thank you very much. I particularly like the oxford journal paper. Not sure I understand why the fresh weight of the green lettuce was higher but ho hum.

danish said:

Thank you very much. I particularly like the oxford journal paper. Not sure I understand why the fresh weight of the green lettuce was higher but ho hum.

Click to expand...

 
High levels of or total exposure to red dominant light will produce stretchier, longer growth, often misinterpreted as "better", but the analysis after this statement of higher fresh weight shows lower levels of "chlorophyll content, total phenolic concentration, total flavonoid concentration, and antioxidant capacity" re: a larger plant on the scale, but with fewer secondary metabolites.

I've played with LED's a fair bit IMHO you are better off with HPS/MH watt for watt (250w or over, under 250w HPS/MH efficiencies drop quickly). Vegetative growth is always good under LED's (Since Lettuce is pretty much pure veg growth they do well) but flowering under LED's yield are always down on HPS/MH especially for a plant like chillies.
 
Whilst it's easy to output the 4 major peaks of chlorophyll A & B with LED's plants use so much more of the spectrum and we have phytochromes & cryptochromes to think about with distinctively different absoption peaks. Never mind the other chlorophyll peaks (It has peaks outside the visilbe light range which are present in daylight and with fluros, MH & HPS).
 
HPS/MH & fluro's are a much fuller spectrum then present LED's can offer making them better for supplemental light than total replacement for the sun. All my plants have shown more vigour, better yields, healthier stockier plants when grown under HID lighting vs LED.
 
Anecdotally my chillies grow twice as fast under HPS as MH watt for watt which suggest they're loving the red light.
 
LED is the future of grow lighting IMHO it's just very much still in it's infancy (We need more wavelengths) and unfortunately grow LED's are marketed using the same principles as an american snake oil sideshow of the 20's and 30's.

at first it seemed leds were going for limiting spectrum(red and blue only) to be the most efficient. 
 
Now if you look at most of the new lights they try to cover much more of the spectrum. uv, violet, blue, royal blue, white, red, far red, infrared in a mixture..... So they are still skipping most of the yellow / green light but providing much more of a spread of light(getting back to emulating sunlight like a fluorescent). 
 
in the normal graph you only see the chlorophyll peaks and how they relate to LED peaks.
But there are many other supporting items that use light as well.


 
 
Many of these lights are available but they are f**king expensive. UV leds are particularly expensive because they can also  be used for sanitization so they are in much demand. Also uv and infrared are like snake oil because you can't see them, you have to have testing equipment to verify it's even working!
 
So you may put all this work and all this money only to find, hey 30% loss from yellow and green light emitted by a cool white / daylight mixture isn't really that bad.

juanitos said:

So you may put all this work and all this money only to find, hey 30% loss from yellow and green light emitted by a cool white / daylight mixture isn't really that bad.

Click to expand...

 
^that. To quote myself, "They're just peppers." LEP may yet prove to make the hottest indoor peppers on paper, but you'll pay about 50$ a pepper

So now that we have established that white light is good and much less complicated (and cheaper). Lets look at led white fixtures.
 
32watts 2800 lumen, about $2.4 per bulb
 
compare to 3w leds, say 14 of them run at 80% so 2.4 watts really. 180-210 lumens each, $0.25 each
So 2500-2900 lumens 33 watts. about 3.5$ per 14.
 
So you say well it's pretty close, maybe leds produce less lumens! and leds are more expensive, and having to diy the fixture is annoying.
 
1. Angle: 120 or 90 degree angle on LEDS so they will only output light downwards, there is 0 loss reflected up and out. T8s output light all around and this is really lossy without a reflector(cheap shop light fixtures), even with a reflector still losing a lot (up to 30%).
 
Once you factor angle, say 30% loss, you get 1960 lumens!
So for leds you would only need 10 3w to be the same.
Lets take our price down now to 2.50$ the same as a t8 bulb(from 10 pack)
Lets take our energy usage down now to 24W.
 
2. Lamp life: Leds are 50,000+ hours, t8s are 10,000 hours. So once you add up the costs of replacing the t8 bulbs 5 times, leds are certainly much cheaper!
 
Wait so now we can figure t8s will fail 5 times before we replace the LEDS..... so t8s for 50,000 hours are 12.5$, leds are still 2.5$ wow maintenance cost is huge.
 
3. Degradation: T8s as commonly designed to degrade 40% over their 10,000 hour life. In the first 2000 hours by 10%!
 
So lets take that t8 lumens and take 10% off then take 30% loss off now we're at 1764 lumens(most of life will actually be much lower)!
LEDS are around 5% over their whole lifespan(at good temperature) so at 2000 hours may be 1%. so 10 leds at minimum is 1800 lumens, more likely we could reduce it even lower to 9 leds drawing 21.6 Watts but lets just leave it at 10.
 
3. Fixture cost: Leds fixture can be expensive though, this is pretty artifical with demand being high and it being a newer technology that people are embracing. so a 2 bulb t8 light fixture is 18$ at lowes. If you DIY your own fixture, lets make one like a tube like t8 bulb. So Alum U ch 4ft is 5$, Driver is 9$, power cord is 1.5$, other materials 2$(solder, thermal adhesive, wire) so 18$ and we can run 20 leds off of it, so same exact cost as the t8 fixture (although much more rough looking, unpainted, etc).
 
So after these 3 factors lets summarize say 50,000 hours of use:
 
Power usage: Led uses 37.5% less enery
T8 32watt x 2 = 64 watt = 3,200 kwh(kilowatthour)
LED 20 watt x2 = 40 watt = 2,000 kwh
in winter my rate is 0.10$ per kwh so 120$ savings!
(in higher energy cost areas savings could be double+)
 
Initial cost:
Fixture = 18$ for both
Bulb: 5$ for t8, 5$ for led
so 23$ is the same
 
Maintenance cost:
Have to replace t8s 4 times = 20$
no replace led = 0$ 
so 20$ savings with led
 
 
But is 140$ spread out over 10 years really that worth it? 
not really if you're a small scale operation with only a couple of lights imo.
 
Say you have 10 of these lights.... 1400$
Say you office building has 500 of these lights..... 70k$
 
*disclaimer, please don't flame me lol. i know its kinda off topic

Lumen ratings on grow lights are a simple gimmick.  PAR ratings and provided light spectrums are the only numbers worth looking when comparing various grow lights, especially with newer lighting technologies like LED, LEC, and DE lights.  LEC lights are now coming with dual spectrum bulbs that are completely changing the grow light industry.  I just replaced all of my HPS/MH lights with LEC 315 lights in my indoor lab and the results will speak for themselves very soon.   

Ignite said:

Lumen ratings on grow lights are a simple gimmick.  PAR ratings and provided light spectrums are the only numbers worth looking when comparing various grow lights, especially with newer lighting technologies like LED, LEC, and DE lights.  LEC lights are now coming with dual spectrum bulbs that are completely changing the grow light industry.  I just replaced all of my HPS/MH lights with LEC 315 lights in my indoor lab and the results will speak for themselves very soon.   

Click to expand...

 
I would be interested to do a grow off with yourself, clones from the same plant you under LEC and me under HPS same wattage to compare yields, flowering times (Including when they go flower), heat (This would be subjective I guess we both send chillies to a 3rd party on here to rate them for heat.)and general vigour/health of the plants.
 
I would suggest we have a 3rd party supply the clones to both of us in the interest of impartiallity but at a push I could supply reaper clones in 8 weeks or so.
 
 
We must NOT forget the phytochromes which PAR and Lumens both totally ignore (Although HPS, MH, Fluro's and probably LEC are probably full of far red 730nm light, LED's will have none unless they have specific led's to produce the far red (A lot do these days).

Vertically Challenged said:

 
I would be interested to do a grow off with yourself, clones from the same plant you under LEC and me under HPS same wattage to compare yields, flowering times (Including when they go flower), heat (This would be subjective I guess we both send chillies to a 3rd party on here to rate them for heat.)and general vigour/health of the plants.
 
I would suggest we have a 3rd party supply the clones to both of us in the interest of impartiallity but at a push I could supply reaper clones in 8 weeks or so.

Click to expand...

 
I would be willing to do that at some point.  My indoor lab can handle ~22 plants and even though it's full right now, I should have some room after the first part of 2015.  My plants start in a custom aeroponic system and then they move into top-drip DTW systems in coco.  
 
I'm not advocating against HPS/MH lights...I still own (2) 400W systems that I use for seedlings and young plants.  I replaced (4) 600W HPS lights with (4) LEC 315W lights, so I'm now consuming half of the power and producing the same amount of heat as (4) 400W HPS lights. 

I'm just very interested to see the difference give us a shout whenever you're ready BUT I don't grow indoors from May to August. I believe I'm pushing the upper end of what you can get from a HPS/MH lamp.
 
I start my plants in fytocell, then move them into fytocell in the main pots but I can do soil or coco. I'll dripper feed (But can handwater at a push). Certainly we should use the same medium and nutrients keep the same ec, ph, etc.
 
Can you hang light emitting ceramics vertically with no shade?
 
this is how I will grow
http://thehotpepper.com/topic/50475-vertical-chilli-grow-indoors-600w-mhhps-lighting/

Vertically Challenged said:

 
I would be interested to do a grow off with yourself, clones from the same plant you under LEC and me under HPS same wattage to compare yields, flowering times (Including when they go flower), heat (This would be subjective I guess we both send chillies to a 3rd party on here to rate them for heat.)and general vigour/health of the plants.
 
I would suggest we have a 3rd party supply the clones to both of us in the interest of impartiallity but at a push I could supply reaper clones in 8 weeks or so.
 
 
We must NOT forget the phytochromes which PAR and Lumens both totally ignore (Although HPS, MH, Fluro's and probably LEC are probably full of far red 730nm light, LED's will have none unless they have specific led's to produce the far red (A lot do these days).

Click to expand...

 
Recent grow on IC, 0.95GPW. For as much as I love CMH I don't even own any yet....