TOO MUCH LIGHT!

[CannaRed]

Miniscule being the key word there.

 

[flylowgethigh]

When the light reflects off the tent walls I think it also becomes polarized, losing as much as 50% on the bounce. Most LEDs have a 120* light cone, so you can see how much is going directly onto the wall.

 

[GoatCheese]

Miniscule being the key word there.

Absolutely. miniscule/little/some is not the same as NONE or no effect at all. Understand the difference? Science and nature does

 

[GoatCheese]

Here’s a bit from a post by OZZ talking about how, if you have the light high enough, you can have it running with more watts compared if you have it dimmed down but closer to the plants without the plants suffering


Think I read another post by someone saying the same thing..
I never owned a light meter and don’t know anything about them or what the correct term is for how photons at canopy level is measured..
Is it PPFD? You can have the higher PPFD reading on canopy level without the plants suffering when you have the light raised high enough so you can run it with more watts, compared to dimming it down and having the light closer to the canopy.

I think I’ve got all my issues sorted out. Several lessons that have been mentioned already here and elsewhere but are easy to overlook and are very important IMO.

1) Keep that light raised high and let them grow into it. Dimming it down and having it close does not work out as well as having it turned up with more power but raised higher. As in I started the plants below (see pic) at only 75w @ a full 36” when they were transplanted at 10” tall, increased slowly to 100w, then 150, 200, 250 and now at 300w. Flipped them to flower four days ago or so, will keep it here until they see beginning bud development then will up it slowly to 400w and keep it there (it’s a 550rspec in a 3x3). Currently at 300w week one of flower still at 30” away and they are doing fine.

https://www.icmag.com/ic/showpost.php?p=8961790&postcount=217


Here’s another poster in the same thread talking about the same thing ..light meter says PPFD should be ok but the plants are suffering under leds/cobs

yeah that is my issue as well. It looks like there is too much light but the meter says it is ok. Only have this with qb,s. Under my blurple (or any other lightsource)i can start seedlings at 300 500 pond without issues....
Or there is something wrong with your lights or we are doing something horribly wrong.

My flowering tent is only 160 cm so I can’t raise my cobs high enough to crank the light to full 225w, so I can’t test this so well, but getting the higher PPFD(?) reading on canopy level without the plants suffering when the light is raised high enough would tell me that something is happening to the photons (eating out some of their energy) when they go thru enough air (atmospheric gasses) before hitting the leaf surface.


Hope you guys can understand what I mean ..it’s abit too technical for my level of English and like I said I have never used a light meter myself.

 

[PDX Dopesmoker]

Someone needs to breed or find some plants that are capable of taking advantage of the high levels of photosynthetically active radiation LEDs can produce without getting too hot, thats the ultimate solution to the issue. Once a plant is found that can eat atmospheric CO2 fast enough to make efficient use of all those delicious photons then everyone can go back to discussing grams/watt and which plants smell the best instead of complaining about the too much light problem.
What landraces handle the heaviest sunlight? High elevation equatorial stuff would be my first guess.

 

[flylowgethigh]

My meter reads the sun in the winter time at 1700 or so. Plants don't like it over 750ish without CO2, per the interweb charts. My little sprouts are happy at 250.

'Splain that to me.

 

[Koondense]

IF you put a red object close to a white wall and aim white light in their direction, why do you think you see some red on the white wall when the light was also white

For the same reason you see the red object as "red". It only reflects the red light, same reflected red light goes to the white wall and back to your eye. "White" is all colors in same proportions.

Cheers

 

[mean mr.mustard]

I switched from CFL's to LED lights not too long ago. My first run with LED's went fine, but on the next two, I kept lowering and lowering the lights, to get them as close to the tops as possible.

By the time I got to the third run, my fan leaves were yellowing and falling off. By the end of that run, there were no fan leaves left.

I just would not believe that the problem could be too much light, because my temps were fine, yes, even at the top of the canopy.

I had to end that run a little early because without fan leaves, there was no more growth.

AFTER that run, I did some research and discovered that, YES, it IS POSSIBLE to give your plants TOO MUCH LIGHT. Even when the temps are down.

So this run, I have the light 18 inches over the canopy like the manufacturer suggests. And things are going much better.

I'm posting this in case somebody might have a similar problem.

This article explains everything- PSA: Too Much Light?*****
*****Okay, as Ronin4life pointed out in post #2, the link doesn't work. But you CAN use your favorite search engine to find it, searching under "PSA: Too Much Light?" The article is on a website called grow weed easy dot com. Thanks to Ronin4life

This thread fell apart seven words into it.



Try "I switched from LED to CMH lights"...

 

[Horselover Fat]

Here’s a bit from a post by OZZ talking about how, if you have the light high enough, you can have it running with more watts compared if you have it dimmed down but closer to the plants without the plants suffering


Think I read another post by someone saying the same thing..
I never owned a light meter and don’t know anything about them or what the correct term is for how photons at canopy level is measured..
Is it PPFD? You can have the higher PPFD reading on canopy level without the plants suffering when you have the light raised high enough so you can run it with more watts, compared to dimming it down and having the light closer to the canopy.



https://www.icmag.com/ic/showpost.php?p=8961790&postcount=217


Here’s another poster in the same thread talking about the same thing ..light meter says PPFD should be ok but the plants are suffering under leds/cobs



My flowering tent is only 160 cm so I can’t raise my cobs high enough to crank the light to full 225w, so I can’t test this so well, but getting the higher PPFD(?) reading on canopy level without the plants suffering when the light is raised high enough would tell me that something is happening to the photons (eating out some of their energy) when they go thru enough air (atmospheric gasses) before hitting the leaf surface.


Hope you guys can understand what I mean ..it’s abit too technical for my level of English and like I said I have never used a light meter myself.

I'm guessing he just had a lower light level at canopy level after raising the lights, or he fixed his feeding so the plants can take all the light. Or perhaps cobs make hotspots? Those are my guesses.

 

[Horselover Fat]

My meter reads the sun in the winter time at 1700 or so. Plants don't like it over 750ish without CO2, per the interweb charts. My little sprouts are happy at 250.

'Splain that to me.

Wow, I wish it was 1700umol in the sun here in winter plants can take more than 750 without additional co2. With the co2 they may photosynthesise faster as they don't run out of carbon. Outside there is much larger air volume and almost always a breeze that will exchange air.

 

[f-e]

Below 600ppfd co2 is pointless, while above 800ppfd it's co2 rather than light becoming your bottleneck. Though 1000ppfd is workable without co2 with good airflow and the right plants.

A skated around it earlier. My OG crossed with an auto, who's likely from the far north, is complaining at 65,000lux which is the full 1000ppfd. While My OG crossed with Afgan heritage is reaching out in 1500ppfd and I don't use co2 as I feel it's pointless and bad for everybody's environment. It's Sats that can take the most light and Indica's that like less. Yet I see this within the mostly Indica's I have.


It's a shame more people don't spend $10 on a light meter. We could have much more meaningful discussions using illumination figures, than watts and guesstimated heights of unknown lights.

This chart is quite useless unless you can actually measure


My 65K/1000ppfd is at the top of the tops. Which may just rot if they got bigger (they would) but my canopy is lower. Maybe 40K giving a 75% growth potential. 30K doesn't make me happy, but it's in the seed vendors ballpark range of results. Most people shouldn't be pushing any harder than that.

 

[f-e]

This thread fell apart seven words into it.



Try "I switched from LED to CMH lights"...

Heathen. Heating up metal till it glows and denying LED is better. I have included your Mercury containing lamps on my chart, but feel you would be better breaking them open to treat syphilis

 

[Loc Dog]

Below 600ppfd co2 is pointless, while above 800ppfd it's co2 rather than light becoming your bottleneck. Though 1000ppfd is workable without co2 with good airflow and the right plants.

A skated around it earlier. My OG crossed with an auto, who's likely from the far north, is complaining at 65,000lux which is the full 1000ppfd. While My OG crossed with Afgan heritage is reaching out in 1500ppfd and I don't use co2 as I feel it's pointless and bad for everybody's environment. It's Sats that can take the most light and Indica's that like less. Yet I see this within the mostly Indica's I have.


It's a shame more people don't spend $10 on a light meter. We could have much more meaningful discussions using illumination figures, than watts and guesstimated heights of unknown lights.

This chart is quite useless unless you can actually measure
[URL=https://www.icmag.com/ic/picture.php?albumid=78998&pictureid=2019659&thumb=0]View Image[/url]

My 65K/1000ppfd is at the top of the tops. Which may just rot if they got bigger (they would) but my canopy is lower. Maybe 40K giving a 75% growth potential. 30K doesn't make me happy, but it's in the seed vendors ballpark range of results. Most people shouldn't be pushing any harder than that.

Is that 1000 uMol's?? Saw video on youtube saying 3000 is max, and figured that would be safe to grow. I do not use CO2, and thinking of buying uMol meter, to setup optimally.

 

[GoatCheese]

For the same reason you see the red object as "red". It only reflects the red light, same reflected red light goes to the white wall and back to your eye. "White" is all colors in same proportions.

Cheers

Look what I replied to Fatsy a page before.

When you light a candle in the dark, it is emitting photons. What light it is supposedly reflecting then. Red hot iron is also emitting photons, not reflecting anything, you can even tell the temperature of hot iron by the color of the photons it is emitting. Atomic matter emits photons.

High energy photons from the sun slam into atmospheric gasses, which in turn emit photons and the atmosphere becomes opaque and we can’t see the stars in space anymore. So, Sun light we see is a secondary effect and the light we see comes from the photons emited by the molecules of the gasses. The sky during the day appears blue because of the color of Oxygen. Oxygen also gives water is bluesish color.

But enough of this cause it’s sort of off topic. If you still don’t wanna believe atomic matter is emitting photons when it’s agitated by higher energy levels of different forms of electromagnetic radiation (light is one of it’s forms, heat is another one), then it’s fine by me.
Peace

 

[flylowgethigh]

I would like a good comparison test of meters. A light meter measuring lumens is not measuring the entire spectrum a plant needs.

You need a sensor that will measure the entire spectrum we want.

Light meter:

PAR meter:

Specs on my little meter:

https://shop.pahydroponics.com/hort...lg-30-uva-supplement-light-shipping-included/

I like the USB 520 version, and may get one (Edit, or may not. They cost $438):

https://www.apogeeinstruments.com/sq-520-full-spectrum-smart-quantum-sensor-usb/

The same company has a temperature sensor that mimics a leaf. I think one of those optical forehead thermometers would work OK, and they are a lot cheaper.

This is what I am using now:

 

[Koondense]

Goatcheese,

it's offtopic and it's wrong, many of the things you explain are incorrect.
There are many ways to emit photons, the main is called black body radiation, plasma is not a black body for example.
Skyes are blue because of nitrogen, not oxigen... and the water is colourless, not blue. Oxygen has nothing to do with it.
Sorry for the tone but i work in a physics lab, sometimes teach physics and feel the need to correct such mistakes.
It's all about qed. And love

Cheers

 

[mean mr.mustard]

Heathen. Heating up metal till it glows and denying LED is better. I have included your Mercury containing lamps on my chart, but feel you would be better breaking them open to treat syphilis

I use LED.

I still use HPS.

 

[PDX Dopesmoker]

Goatcheese,

it's offtopic and it's wrong, many of the things you explain are incorrect.
There are many ways to emit photons, the main is called black body radiation, plasma is not a black body for example.
Skyes are blue because of nitrogen, not oxigen... and the water is colourless, not blue. Oxygen has nothing to do with it.
Sorry for the tone but i work in a physics lab, sometimes teach physics and feel the need to correct such mistakes.
It's all about qed. And love

Cheers

All of those "I know how everything works because of muh academic qualifications" rumors that people who've purchased academic qualifications circulate are plainly false. Being trained to rigidly regurgitate textbook dogma often turns people into useless, narrow-minded idiots who lose the ability to observe reality when reality and textbook dogma disagree. If academic qualifications in physics correlated with ability then why are uneducated people like James Watt, Michael Faraday, Thomas Edison, Benjamin Franklin, The Wright Brothers, Lewis Latimer, Clyde Tombaugh, Guglielmo Marcon, Alexander Graham Bell all bigger names than their more highly qualified contemporaries?
Pythagoras was so uneducated that he never even learned the pythagorean theorem in school.

 

[Koondense]

What is your point pdx?
Let people believe they're right when they hold unfunded beliefs?
We're steering downhill it seems.



Cheers

 

[Horselover Fat]

What is your point pdx?
Let people believe they're right when they hold unfunded beliefs?
We're steering downhill it seems.



Cheers

Goaty is obviously trolling though so don't get sucked into it. There is no way anyone could come up with that many "facts" that are all wrong unless they are trolling.