Just one broad spectrum bulb for veg & flower?

[tj Wise]

I was reading stuff on the internets... so many opinions... a guy was saying we should use just one type of bulb that emits both the red and the blue spectrums. Has anyone heard of this? Would it save money or be more efficient?

 

[urbanfog]

Ceramic Metal Halide has a much broader spectum.

 

[MedicineFarm]

I was reading stuff on the internets... so many opinions... a guy was saying we should use just one type of bulb that emits both the red and the blue spectrums. Has anyone heard of this? Would it save money or be more efficient?

try a dual arc.

 

[chazbolin]

The sun is broad spectrum. Growing plants indoors under broad spectrums mimics natural conditions.

 

[sedate]

If you want to use a single bulb for your entire cycle, use a standard 2000K HPS.

Dual-arcs look cool but are really just gimmicky, and CMH are for parking lots and security lighting.

HPS bulbs veg fine and have plenty of blue spectrum for functional early stage growth. Not perfect since they can cause some inter-nodal stretch that MH's do not, but this is really not a big issue, particularly for properly trained plants.

The sun is broad spectrum. Growing plants indoors under broad spectrums mimics natural conditions.

"Natural Conditions" is not the desirable data point here. We want lots of red and (at least some) blue, with no energy (read: electricity) wasted on other spectral production.

 

[MedicineFarm]

try an HPS for one round then try a dual arc the next round, then you will have an answer.

 

[chazbolin]

Sedate: You are laboring under old science. There is ample data to support the need for green light as a necessary component for optimum photomorphogenesis. As broad spectrum goes the plants finish differently than under narrow chromatic approaches such as straight HPS in flower. CBD:THC ratios under HPS that might range 8:1 for example I've seen come in closer to 1:1 under broad spectrum. The plant will defend itself from the presence of UV-B by creating more trichomes and the trichomes they produce will be hard cut geometry.

LED grow light manufacturers are beginning to recognize the importance of green light and they are adding more white into their designs. Which as anyone who has ever grown under a magenta colored LED panel will tell you is a welcome improvement in not only plant response but to those of us who tend to our plants in unnaturally lit conditions.

http://msue.anr.msu.edu/news/green_light_is_it_important_for_plant_growth

 

[20kwDreamer]

I like using a 1:1 mix of Eye Hortilux MH and HPS for the whole run. I hang my 1k's centered over 5x5

 

[deacon1503]

Sedate: You are laboring under old science. There is ample data to support the need for green light as a necessary component for optimum photomorphogenesis. As broad spectrum goes the plants finish differently than under narrow chromatic approaches such as straight HPS in flower. CBD:THC ratios under HPS that might range 8:1 for example I've seen come in closer to 1:1 under broad spectrum. The plant will defend itself from the presence of UV-B by creating more trichomes and the trichomes they produce will be hard cut geometry.

LED grow light manufacturers are beginning to recognize the importance of green light and they are adding more white into their designs. Which as anyone who has ever grown under a magenta colored LED panel will tell you is a welcome improvement in not only plant response but to those of us who tend to our plants in unnaturally lit conditions.

http://msue.anr.msu.edu/news/green_light_is_it_important_for_plant_growth

In addition to covering themselves in trichomes as a "sun screen", don't trichomes also require UV to produce THC within the glandular head?

If so, would those 10k MH bulbs accelerate this?

 

[sedate]

Sedate: You are laboring under old science.

I am laboring under old science huh? LMAO.

Then why does your link cite a source from 1972?

There is ample data to support the need for green light as a necessary component for optimum photomorphogenesis.

I'm sorry but what you linked to was a smallish post-grad science project. Which certainly does not qualify as "ample data"... a post-grad science project into the relative veg speed of salvia/petunia/tomato plants grown out of seedlings for all of six weeks hardly qualifies as irrefutable compelling data.

Secondly, if you actually read that thing you linked too, it tells you to use blue lights for shorter, bushier, stackier plants:

Therefore, blue light suppressed extension growth more than green light in an enclosed environment

The entire reason we use MH's for veg is to stack internodes as close together as possible. This is highly desirable for dense cola formation when you are dealing with the vagaries of artificial lighting. This is what we want.

. Twenty-five percent green light could substitute for the same percentage of blue light without affecting fresh weight. However, the electrical efficiency of the green LEDs was much lower than that of blue LEDs.

Translation: You could replace blue with green with largely the same results if you want to waste electrons

Lastly, let's take a look at that picture from the experiment:

http://msue.anr.msu.edu/uploads/images/Plant Ag/2-6SalviaHEIDI.jpg

See that first plant? See how the FOLIAGE is the same as the others? The STEMS are just longer? So the green is stretching the plant's internodal lengths over the comparable blue input. Which we could get anyway with a standard HPS.

As broad spectrum goes the plants finish differently than under narrow chromatic approaches such as straight HPS in flower. CBD:THC ratios under HPS that might range 8:1 for example I've seen come in closer to 1:1 under broad spectrum. The plant will defend itself from the presence of UV-B by creating more trichomes and the trichomes they produce will be hard cut geometry.

What? Are you saying here? You do understand that more UV-b will come off a HPS or MH than some green-lit LED panel right? You know the electromagnetic spectrum is UV->blue->green right?

In addition to covering themselves in trichomes as a "sun screen", don't trichomes also require UV to produce THC within the glandular head?

If so, would those 10k MH bulbs accelerate this?

10K Mh's are finishing bulbs. Last week of flower type of thing.

I suppose I would think that if the plant is expending energy on resin production for protection from UV-b - then that light spectrum would not be particularly 'nutritious' for the plant..

 

[chazbolin]

Sedate: To my knowledge the 1972 McCree curve is still the industry standard for plant relative sensitivity absorption. If there have been improvements they have been subtle.

You made an absolute statement where you consider certain spectrums 'unneccesaary' and you would not 'waste energy (read: electricity) on other spectral production. Perhaps you would provide me with what you consider the ideal spectral distribution your lamp would produce overlayed on the net sensitivity curve of cannabis. I'd be interested in where that energy would be saved with the technology you propose.

I have a pretty sound understanding of the electromagnetic spectrum and would correct you in that the UV-Green you suggest consists of the PAR spectrum is actually UV-FR. Also the amount of energy that any HPS emits in the 400-500nm regions is negligible which is why broadening the spectrum into the UV-B regions while flowering a secondary source such as LED, MH or plasma is used. You can see this by the marketing that Gavita is currently using with their new DE1000 HPS lamps in that they recommend adding their 300 watt plasma to pick up UV-B regions as a way to increase crop quality over straight HPS. Of note: on page 3 of the link Gavita uses the quantum version of McCree curve in their literature as well.

http://www.emagcloud.com/gavita/Gavita_Holland_catalog_2012__North_America/index.html#/6/

 

[basement bob]

Phillips 315W Agro for the win!
Yields great, lots of trichomes and great aroma.

 

[The Terps]

I got here a little late. Simple answer mh or hps or dual arc de all work well for both veg and flower. I have a friend who really likes the eye hortlux blue bulb for both stages over mh and hps

 

[diamond2.0]

I been growing with cmhs for 12 years. Much better expression and more usable light to the plant with cmh. Wish they came in a 1k. I Have this triple 400 hood i love to use better than my 1k any day !Ive tried even putting a hps with a cmh and went back to cmh. Seams like dull light hps has to me. I cant handle it .lol. I started with hps. Since they dont make this 400 i use any longer i think i will try the 315 mentioned next time maybe. Can i modify my magnetic 400 to run with them is my question? lol

 

[basement bob]

I hesitate to admit,

I can look at a bare 1000W HPS for about X seconds.

I can look at the 315W Philips for about 1/10 X.

I can't look at the sun.

Very scientific.

Bob

 

[The Terps]

Plants do have eyes though and use light differently than humans don't base it off what simply looks brighter

 

[basement bob]

@The Terps
Sarcasm runs deep in my people. Bright and hot to humans is not great for plants.

Check out the Ceramic metal halide thread. I'm less sarcastic.
Bob

 

[Coir]

View attachment 446294 I been growing with cmhs for 12 years. Much better expression and more usable light to the plant with cmh. Wish they came in a 1k. I Have this triple 400 hood i love to use better than my 1k any day !Ive tried even putting a hps with a cmh and went back to cmh. Seams like dull light hps has to me. I cant handle it .lol. I started with hps. Since they dont make this 400 i use any longer i think i will try the 315 mentioned next time maybe. Can i modify my magnetic 400 to run with them is my question? lol

There is an 860W Phillips CMH that runs off of a 1000W magnetic MH ballast. Vertical only though so you need high ceilings!

 

[basement bob]

But Philips 315w is using UV-block quartz tube, it is for commercial lighting to protect human eyes, they never thought it will be used as grow light , we need UVA for plants

I was unaware of this. I will look in to it now. Why is it billed the " Elite Agro" bulb? I believe it's for commercial agriculture and Horticulture.

I don't see quartz on this pdf, but I'm wrong a bunch.

Bob

 

[MedicineFarm]

I was reading stuff on the internets... so many opinions... a guy was saying we should use just one type of bulb that emits both the red and the blue spectrums. Has anyone heard of this? Would it save money or be more efficient?

So the reason i prefer the dual arc is that you don't have one physical piece that is trying to do both tasks. throwing out reds,yellows blues and some greens. the dual arc contains a metal halide "filament" AND the quartz "filament". this allows them to do their specific jobs with in one envelope. IMHO this is what makes them more specialized than the newer style full spectrum lamps or the "blue" labels that are out there. if you can, get a dual arc and an HPS as you should have a back up any ways in case you blow a lamp, then try both. also most dual arcs spec out 400w worth of MH and 600w worth of HPS which is an awesome balance leaning towards the HPS. look up 247garden for a good price on an awesome lamp.here is some mexican weed from underneath a dual arc.