LED light intensity

wietefras

wietefras

Well-Known Member
In.Home.Rhizome said:
Does that mean that to plants that photons are photons or can a plant max out at a one wavelength and not at another?
I mean do plants have different dli requirements and limitations at different wavelengths? Or is it cumulative total photons regardless?
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Plants have different pigment cells which absorb different wavelengths. Also plants become less efficient when dealing with higher intensities. So it makes sense that flooding just one pigment will make it less efficient than spreading out the spectrum over all pigments.

I have always had the idea that this is one of the reasons why plants under blurple lights are so prone to bleaching. Those fixtures emit solely/mostly red and blue light (ie very narrow spectrum) and even at rather modest light intensities the light becomes to intense for the plants (causing bleaching).

Still there is obviously more to it than that.
 
Moflow

Moflow

Well-Known Member
wietefras said:
Plants have different pigment cells which absorb different wavelengths. Also plants become less efficient when dealing with higher intensities. So it makes sense that flooding just one pigment will make it less efficient than spreading out the spectrum over all pigments.

I have always had the idea that this is one of the reasons why plants under blurple lights are so prone to bleaching. Those fixtures emit solely/mostly red and blue light (ie very narrow spectrum) and even at rather modest light intensities the light becomes to intense for the plants (causing bleaching).

Still there is obviously more to it than that.
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Would another reason for the bleaching be the magnifying lenses on the burples?
Recommended hanging height usually around 18" plus very high central par readings
Here's a 150 3 watt epiled / bridgelux full spectrum board with the lenses off at 30 watts.
Nice par reading at ~ 7 - 8" not a great spread through, enough for side light for one plant
20181230_193455.jpg .
 
Rocket Soul

Rocket Soul

Well-Known Member
wietefras said:
Plants have different pigment cells which absorb different wavelengths. Also plants become less efficient when dealing with higher intensities. So it makes sense that flooding just one pigment will make it less efficient than spreading out the spectrum over all pigments.

I have always had the idea that this is one of the reasons why plants under blurple lights are so prone to bleaching. Those fixtures emit solely/mostly red and blue light (ie very narrow spectrum) and even at rather modest light intensities the light becomes to intense for the plants (causing bleaching).

Still there is obviously more to it than that.
Click to expand...
Im of this opinion aswell. Sunlight doesnt seem to ever bleach a plant even though its very intense. And it has a very broad spectrum.
Also, CMH has a very broad spectrum and it seems like CMH often overperforms its theoretical numbers.
 
P

pollen205

Well-Known Member
Have 4 citizen 1212 3500k and 84 w is the minimum that I can set on meanwell driver...

Is it overkill for seedlings...Can I start to finish with cobs...
If is overkill can I make some thing to help plant at this stage... Light very high in tent or put transparent cup on top of the plant to hold moisture..or some advice that you have. I don't have propagator...

Happy growing :)
 
Moflow

Moflow

Well-Known Member
pollen205 said:
Have 4 citizen 1212 3500k and 84 w is the minimum that I can set on meanwell driver...

Is it overkill for seedlings...Can I start to finish with cobs...
If is overkill can I make some thing to help plant at this stage... Light very high in tent or put transparent cup on top of the plant to hold moisture..or some advice that you have. I don't have propagator...

Happy growing :)
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Any pictures?
Yea, you can go from start to finish with the cobs.
What size are your seedlings? How many leaves? Container size? Is the tent warm?
At 84 watts 18" away I'd say and keep an eye on them
 
In.Home.Rhizome

In.Home.Rhizome

Member
wietefras said:
Plants have different pigment cells which absorb different wavelengths. Also plants become less efficient when dealing with higher intensities. So it makes sense that flooding just one pigment will make it less efficient than spreading out the spectrum over all pigments.
Click to expand...
That makes sense, I guess there are all sorts of things far as how spectral ratios affect each other to consider.
I mentioned earlier I read someone here say that there is a marked leaf temperature rise when the saturation of light reaches a point where efficiency drops off....if that's true u cld maybe use that to help monitor the saturation of the plants and work out favorable blends of spectrum which wld be cool I'm sure if it's correct it's probably common knowledge to some lol! bongsmilie
 
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Jeeyah

Jeeyah

Well-Known Member
Anyone know of any reason why my plants would just mutate and stress out after changing a light? Swapped out a 4 COB light with a 12 COB light same wattage (300 watts. This is in a 4.5 x 9.5 tent. The canopy area is about 50” by 100.” This is in the center of 4 other (4) COB lights (28 total 5 fixtures total). It worked great with 20 COBs (all 3000K)( 20 total) for years. I recently broke that light down to (6 CXB3590 3500K). (22 total) Had some nice Cali Connection seedlings growing. (Lost my genetics) This tent would kill a plant in 3 days. Put them in flower.....it actually started growing seeds in early bloom. Then, I recently got some clones. They’re on day 19. One of them is starting to grow fat seeds bulging out of calyxes. I see some mutated growth. The light is dimmed down to 120 watts. With the 6 COB light on the middle I could veg. But, if I turn up the light in the center I start seeing mutated growth. This light minus the overlap of the other lights is covering about a 50” by 38” area.

I ordered 4 (3000K) COBs. I have a 4x8 Tent next to that one with 24 (3000K) at much higher wattage and it works great. Healthy perfect leaves. I have a room filled with (3500K) thats been working great for years. 5000K for veg works great.

Any help would be greatly appreciated. One of the COBs blew. This was an old light with the kapton tape and Alpine 11s. I figured I’d upgrade. The only differences I can think of is the 3500K and 3000K mix. And, it has a white tray instead of a black tray which is much more reflective. But, that tent always had a white tray.

Thank you in advance.
 
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Moflow

Moflow

Well-Known Member
Jeeyah said:
Anyone know of any reason why my plants would just mutate and stress out after changing a light? Swapped out a 4 COB light with a 12 COB light same wattage (300 watts. This is in a 4.5 x 9.5 tent. The canopy area is about 50” by 100.” This is in the center of 4 other (4) COB lights (28 total 5 fixtures total). It worked great with 20 COBs (all 3000K)( 20 total) for years. I recently broke that light down to (6 CXB3590 3500K). (22 total) Had some nice Cali Connection seedlings growing. (Lost my genetics) This tent would kill a plant in 3 days. Put them in flower.....it actually started growing seeds in early bloom. Then, I recently got some clones. They’re on day 19. One of them is starting to grow fat seeds bulging out of calyxes. I see some mutated growth. The light is dimmed down to 120 watts. With the 6 COB light on the middle I could veg. But, if I turn up the light in the center I start seeing mutated growth. This light minus the overlap of the other lights is covering about a 50” by 38” area.

I ordered 4 (3000K) COBs. I have a 4x8 Tent next to that one with 24 (3000K) at much higher wattage and it works great. Healthy perfect leaves. I have a room filled with (3500K) thats been working great for years. 5000K for veg works great.

Any help would be greatly appreciated. One of the COBs blew. This was an old light with the kapton tape and Alpine 11s. I figured I’d upgrade. The only differences I can think of is the 3500K and 3000K mix. And, it has a white tray instead of a black tray which is much more reflective. But, that tent always had a white tray.

Thank you in advance.
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I don't think it's a spectrum change causing your problem.
I clone n veg with 3000k 3500k mix, late veg, early flower 3000k and late flower with 3000k, 3500k and 5000k and full spectrum light.
How far away are your lights from plants?
Watts per sq ft?
Where'd you get your clones? Wheres the pollen coming from? Why are they seeding?
Are you sure they have seeds?
Any pics?
Just trying to get a clearer picture of what's going on :lol:
 
Jeeyah

Jeeyah

Well-Known Member
Moflow said:
I don't think it's a spectrum change causing your problem.
I clone n veg with 3000k 3500k mix, late veg, early flower 3000k and late flower with 3000k, 3500k and 5000k and full spectrum light.
How far away are your lights from plants?
Watts per sq ft?
Where'd you get your clones? Wheres the pollen coming from? Why are they seeding?
Are you sure they have seeds?
Any pics?
Just trying to get a clearer picture of what's going on :lol:
Click to expand...
1.) Depending on the plant going in to die, 18” or so.
2.) For about 3 years it was 1100 watts (34 watts/ sq foot) Now the center light is dimmed down and it’s about 29 watts/ sq foot.
3.) After losing my genetics. I bought Cali Connection seeds. Gold Line. Vegged 7 plants. A few weeks into bloom all the buds had seeds. No male parts. No hermie bananas. Threw that in the trash. I got the clones from a guy I looked up to online when I started growing. His place wasn’t clean. I knowingly brought thrips and gnats into my garden. Got rid of the thrips. Gnats. Fuckers. Now powdery mildew popped up. I’ve never had pests or mold before this. He does do a lot of his own crosses. The 2 large plants in there are definitely crosses he made. They are on day 19 and I’ve probably pulled about 10 seeds out of that plant. They are usually found on the lower part of the plant in a bulging calyx.
4.) Definitely seeds.

5.) I found some old pics of the Neville’s Haze x Mango that died in there. I have a video of the WiFi, Sour D, and Super Lemon Haze that died in there. The only reason why I still have my Larry is because I moved it out of that tent back to my little veg tent and it slowly recovered. I’ve recently had a successful harvest in my 2 other spaces. Larry only. I recently vegged up those 10 clones in that tent.

I’ll post some pics n a little while. They’re very, very ugly. Heartbreaking. Green vegetation that’s curled back and twisted with swollen cracked stems. Looks poisoned. It was so bad I was convinced I had an insect or something. After hurting my eyes and inspecting the coco and foliage for months with 2 different microscopes I found nothing. All the other rooms work fine. The following pics are from the 12 COB light. I can veg a plant with the 6 COB light. But, with all the lights cranked I start to see some mutated growth similar to those pics.
 

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