Lumens, Lux, and Adding It all Up

[ceestyle]

I've Gotta A Pretty Simple Question.

Is There A Maximum Level Or PEAK Of Light A Single Plant Can Photosynthesize Or Use?

Yes, but with any light source that we use, you will cook the plant with IR and UV before you can reach that point.

The way to determine that experimentally would be to monitor growth as a function of monochromatic light, such as those produced by lasers or LEDs. Then you are not increasing the intensity of other energies of radiation with those that are relevant for photosynthesis.

 

[Ganjaglutin]

Like, If You Had Four 1000 W Sonagro HPS Bulb Over A Single Plant???......

 

[ceestyle]

that's not a good experiment. you'd cook the plant.

 

[ceestyle]

That is one hell of a serious answer there, cee. You are helping me get to the meat of what I'm trying to formulate in my head. I only have a very rudimentary light meter, and any/all sunlight pegs it high. I've also been wondering how greenhouse conditions would affect this plant, presuming it absolutely requires a barest minimum of five hours direct sunlight. Wouldn't it mimic shade? If so, how deep the shade (again, presuming this is a standard type of greenhouse of the type where other flowering plants can be grown)?

Look in my gallery, you'll see the current growing conditions. Been out there since seedling stage, but my husband just built me a rolling shelf unit that effectively doubles my usable floor space. Been utilizing LST as well. I also started a thread on the sexing process, did this after separating plants based on physical expression (phenotype?) in terms of growth habit and leaf structure. This will allow for some serious culling.


If I could easily take my own measurements, I've surely got the time. I just don't have the equipment (unless the camera has features I could use, Canon Rebel series DSLR). I do have fun turning the lens backwards for super macro close-ups.

Thanks for this, cee, this is very rep-worthy stuff.

I'm checking out your gallery right now.

A good first step would be to grab one of these or something like it: Amazon.com: Mastech Professional Luxmeter, LX1010B: Home Improvement

Then monitor intensity vs. hour of day, do the same for the grow space you were using, and construct a plot like the one in my previous post. That will get you a big jumpstart on figuring out wth is going on. You can even do the measurement shelf by shelf!

 

[Ganjaglutin]

And If The Lights Were Relatively Far From The Plant With GREAT Ventilation And Fans?

 

[ceestyle]

And If The Lights Were Relatively Far From The Plant With GREAT Ventilation And Fans?

then you might as well use a smaller light.

all the radiation that is cooking the plant diminishes over distance the same way that the radiation that helps the plant is. get it?

 

[Ganjaglutin]

WELL THEN!! Lol, If It Was Possible To Do It Without Frying The Plant...

 

[On3Tim3OnLy]

the understanding of lumens::

Plant growth involves the conversion of light energy into plant-building materials. Two factors are important for optimal growth. In the first place, the light intensity. Light intensity is expressed in 'lumens'. At least 50,000 lumens are needed for growing indoors. It's not sufficient to add up the number of lumens listed by the manufacturer for each lamp. The total number of lumens given off is depends strongly upon good reflection, and proper connecting fixtures and starter ballasts for the lamps. The quality of the reflector used, and the connecting fixtures and ballasts determine the light yield for the greatest extent. For those reasons, self-built sets and home-designed illumination often deliver a lot less light yield than lamps being used in professional horticulture. We can improve the light yield in our grow room by applying reflective material. We haven't painted the walls of the room matt white, and used reflector caps for the lamps for nothing! The second important factor is the wavelength of the light. For the production of chlorophyll, and an optimum photosynthetic reaction, light from the blue spectrum (445 nanometres), and light from the red spectrum (650 nanometres) is necessary. Blue light ensures optimal phototropism. Phototropism is the phenomenon which causes plants to grow towards the light, and to spread their leaves in such a way to receive the most light.

 

[ceestyle]

the understanding of lumens::

Plant growth involves the conversion of light energy into plant-building materials. Two factors are important for optimal growth. In the first place, the light intensity. Light intensity is expressed in 'lumens'. At least 50,000 lumens are needed for growing indoors. It's not sufficient to add up the number of lumens listed by the manufacturer for each lamp. The total number of lumens given off is depends strongly upon good reflection, and proper connecting fixtures and starter ballasts for the lamps. The quality of the reflector used, and the connecting fixtures and ballasts determine the light yield for the greatest extent. For those reasons, self-built sets and home-designed illumination often deliver a lot less light yield than lamps being used in professional horticulture. We can improve the light yield in our grow room by applying reflective material. We haven't painted the walls of the room matt white, and used reflector caps for the lamps for nothing! The second important factor is the wavelength of the light. For the production of chlorophyll, and an optimum photosynthetic reaction, light from the blue spectrum (445 nanometres), and light from the red spectrum (650 nanometres) is necessary. Blue light ensures optimal phototropism. Phototropism is the phenomenon which causes plants to grow towards the light, and to spread their leaves in such a way to receive the most light.

did you read the rest of the thread?

 

[ceestyle]

WELL THEN!! Lol, If It Was Possible To Do It Without Frying The Plant...

At some point, you would exceed to capacity of the supporting metabolic pathways of the carbon cycle. Say you're making a computer, and the part you have the least of is generally processors, so you assemble the computer as soon as you have processors available. Then, if you have as many processors as you want, you will eventually run out of some other part, say memory or motherboards. Not a very good analogy, but it's 8:30 in the morning. If the plant could process infinite light, growth rate would be limitless.

I've also read that some of the higher energy visible radiation causes a degree of acceptable cellular damage. If this is the case for visible light within the usable spectrum, increasing light intensity will also increase this rate of damage, which may either degrade light-processing capacity or otherwise hurt the plant.

 

[Seamaiden]

did you read the rest of the thread?

I.... don't think so. Ya know... I see a thesis in here somewhere.

 

[DiZzYNaTiOn]

cee, someone asked you this question already but ill ask it a diff. way, "What is the least amount of light for one plant (cost reasons, and space reasons) to veg. healthy, and then then for flowering getting an average yeild from CFL's.

I used 5 42watt CFLs and 2 4' work flors which has worked wonders for me, and with only 3500 lumens based apon not being able to add lumens which is what alot of people say, and they also say you need at least 30,000 lumens to 50,000 lumens to grow indoor. I just got what i could and here is a few pics. Im glad someone finally knows what there talkin about.

 

[Seamaiden]

Sheesh, YEAH they look like they're liking whatever it is you're doing.

 

[ceestyle]

cee, someone asked you this question already but ill ask it a diff. way, "What is the least amount of light for one plant (cost reasons, and space reasons) to veg. healthy, and then then for flowering getting an average yeild from CFL's.

I used 5 42watt CFLs and 2 4' work flors which has worked wonders for me, and with only 3500 lumens based apon not being able to add lumens which is what alot of people say, and they also say you need at least 30,000 lumens to 50,000 lumens to grow indoor. I just got what i could and here is a few pics. Im glad someone finally knows what there talkin about.

I do not proclaim to be an expert on 'minimum light requirements' because I do not have the experience trying to chintz my plants of light for the sake of my wallet. Also, "to veg healthy" is extremely vague. I mean, a plant could survive on one 13W bulb and probably be healthy, but just not grow quickly. Add more light, get more growth.

More accurately, it totally depends on how large the plant is - height and width - as that determines how you must arrange the lights. With 2-3 x 42W you could veg a plant nicely to a foot or so, but with the equivalent amount of light in one fluorescent, you would not be as successful.

All that said, you have a good amount of light, and it would probably suffice for a shorter plant, perhaps even to flower, but with how tall your plant is, those lower buds are just not going to see enough light. If you lollipopped it, that would work. Otherwise, you need something that will get direct - not reflected - light to the sites on lower branches.

They look very nice, btw.

 

[DiZzYNaTiOn]

Well to answer that guys question about minimal lighting, i would say go no less then 3 32w CFLs to get the plant about 18"-20". Witch is what i use for this Afghani below, and i got 7 clones off the bottom part. Then switch to 3000K to flower. But anyways thats the lighting i used for so many different reasons, and im sure there are more growers out there that have there reasons not to use tons of lights and tons of plants. So hopfully this info. helps some of you guys out there just trying for get some smoke growin at home.

Recap (3) 32W CFL's 6 weeks got me this

 

[ceestyle]

Exactly. it's all about what is acceptable to you. Please don't get me wrong - that's a cute, healthy plant - but if I spent 6 weeks growing that I would be unsatisfied.

 

[DiZzYNaTiOn]

Exactly. it's all about what is acceptable to you. Please don't get me wrong - that's a cute, healthy plant - but if I spent 6 weeks growing that I would be unsatisfied.

It would be much bigger if i was doin 24on but this was 16-8 and the last 2 weeks was 12/12... Sorry forgot to add that info. Shes got some beautiful white hairs showin ! But yea if the question was whats the lease amount of light needed to grow but grow at the same rate i wouldnt know. I just know what ive done.

 

[Shaun420man]

Ive grown with MH..Ive Grown With HPS.. Ive Grown with CFL's ..Been Growing for 20 years. Each Grower has his/her own style. I currently use CFL's with AMAZING results all the way to flower. I use a basic lulmens per sq ft measure. I swap kelvin as i see fit.

 

[homegrownboy]

Yes i agree about the cfl's haveing great results for seedling-veg stages, i too have also been growing for 20+ years and have always used MH/HPS...i like how the plants stay shorter, but get ALOT bushier.

BUT...when it comes to flowering...so far...nothing beats a good ol' HPS.

 

[Mr. Maryjane]

hey, can you hook up more than one light to a ballast, and if so, how do you know how many you can hook up.