TOO MUCH LIGHT!

[Koondense]

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.

I would love this to be the truth but i suspect it's not the case.Anyway, i'm always happy to be constructive, but maybe this is not the time and place for that.
In case anyone wants clarifications or anything, pm is the way.


Cheers

 

[Horselover Fat]

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.

1000ppfd at canopy is pretty much the most you would want. They can take a bit more, but you would flower very well (perhaps even better) at a bit lower level. 3000 ppfd would be just way too much. It would be a waste even if you met the plant's needs at that light level. Full sun at equator is about 2000ppfd.

 

[GMT]

The refraction of the light generates the colour as it passes through water(oceans or atmosphere). The other colours are bent away, which is how sunsets only appear as the sun is low in the sky. The red colours bend around the earth. The blue colours travel in straighter lines. The atmosphere is not opaque lol.
Not being funny, but quoting science, or correcting science, esp if teaching science, you kind of have to get it right.

 

[Gaussamer]

The refraction of the light generates the colour as it passes through water(oceans or atmosphere). The other colours are bent away, which is how sunsets only appear as the sun is low in the sky. The red colours bend around the earth. The blue colours travel in straighter lines. The atmosphere is not opaque lol.
Not being funny, but quoting science, or correcting science, esp if teaching science, you kind of have to get it right.

Not trying to jump on you, but he needed no correction. The sky is blue because of the refractive index of Nitrogen in the air, called Rayleigh scattering. It's red at sunset and sunrise because of Willis-Tyndall scattering, a different though related mechanism. Our sun's light does not bend observably to us around the earth as distant bodies can be observed to cause redshift. It's all in the air and the atmosphere's refractive index.

 

[GMT]

It doesn't bend because of gravity, it bends due to the same principles as a rainbow splits its light.

 

[flylowgethigh]

Cloudy day yesterday and the sky was only 200 umols. Watching the leafs on my sprouts was a good way to see too much light power going down, compared to how much light the sprouts could process. As they make roots I think they can take more. I think the leaf flatness compared to reaching for the sky, as in "I give up", is a decent way to tell on the sprouts, if there is too much. The lankyness was a too little light indicator.

The Growers Choice light controller I have is already obsolete in my opinion. I want it controlling on leaf temp at the center of the tent, and adjusting umols to meet that temp.

 

[mean mr.mustard]

If science is scary, there's always religion.

 

[CannaRed]

Cloudy day yesterday and the sky was only 200 umols. Watching the leafs on my sprouts was a good way to see too much light power going down, compared to how much light the sprouts could process. As they make roots I think they can take more. I think the leaf flatness compared to reaching for the sky, as in "I give up", is a decent way to tell on the sprouts, if there is too much. The lankyness was a too little light indicator.

There's another thing that folks argue about. I always heard that if the plants had their leafs up it meant they were happy.. but it does seem to make sense that if they were getting too much light, that they would alter the angle away from the incoming sun.

I remember an old post from Coot ( I think it was in the ROLS thread, where he was asking about the leaves praying after an application of something...( I think it was aloe and silica?) He said it lasted for days. What would this mean? That the application caused the plant to be more sensitive to light?
Does anyone dim down their lights or raise raise their lights when they see praying leaves? What happens? How long does it take for leaves to flatten back out?

 

[Horselover Fat]

There's another thing that folks argue about. I always heard that if the plants had their leafs up it meant they were happy.. but it does seem to make sense that if they were getting too much light, that they would alter the angle away from the incoming sun.

I remember an old post from Coot ( I think it was in the ROLS thread, where he was asking about the leaves praying after an application of something...( I think it was aloe and silica?) He said it lasted for days. What would this mean? That the application caused the plant to be more sensitive to light?
Does anyone dim down their lights or raise raise their lights when they see praying leaves? What happens? How long does it take for leaves to flatten back out?

My plants haven't really been praying since I switched to dwc from soil. I always thought they seemed healthy when they did pray, but perhaps they pray when they are evaporating more than their roots can handle.

I just tried letting my plants grow close to the lights, but they didn't start praying even though the light level got too high. Instead the leaves twisted fingers trying to find an angle with less light... Fat chance The uppermost leaves did get messed up, but I was going to remove them anyway. Experimenting is what it's all about.

 

[flylowgethigh]

That would be interesting to hear. I am very new to this, and just making observations. I watch the commercial corn next door as it reacts to weather and water conditions, and it definately changes the leafs depending on it's needs.

The curled up fingertips on the serrations were another clue to more light than it wanted.

 

[CannaRed]

That would be interesting to hear. I am very new to this, and just making observations. I watch the commercial corn next door as it reacts to weather and water conditions, and it definately changes the leafs depending on it's needs.

The curled up fingertips on the serrations were another clue to more light than it wanted.

I remember that after Coot made that post, other members replied with anecdotes about what they saw cause it. I remember one post saying that they seen it after the plants had a good soaking.
It's all very interesting to think about

 

[Cactus Wes]

LEDs have a higher rate of light penetration than HIDs. LED grow fixtures will always be placed further away than HIDs. CFL bulbs can be placed closer if you are running out of space in your grow. But if you feel the need to drop the lights, then perhaps what you really desire is a more powerful light.
But I'm with you, try raising the lights. If it creates large inter nodal space from stretch though; you may consider more power.

 

[mean mr.mustard]

I remember that after Coot made that post, other members replied with anecdotes about what they saw cause it. I remember one post saying that they seen it after the plants had a good soaking.
It's all very interesting to think about

I have a theory that they are trying to transpire moisture by exposing their stomata to the breeze.... much like they fold their leaves together and tilt them down to reduce transpiration, just the opposite.

A good soaking resulting in praying leaves would support the theory.

Okay off topic, I'll see myself out.

 

[Horselover Fat]

I have a theory that they are trying to transpire moisture by exposing their stomata to the breeze.... much like they fold their leaves together and tilt them down to reduce transpiration, just the opposite.

A good soaking resulting in praying leaves would support the theory.

Okay off topic, I'll see myself out.

Leaves usually droop afrer watering in soil for a while in my experience.

 

[Horselover Fat]

LEDs have a higher rate of light penetration than HIDs. LED grow fixtures will always be placed further away than HIDs. CFL bulbs can be placed closer if you are running out of space in your grow.

Please explain how leds have a higher rate of penetration and why they should be placed higher than hids. CFL can be placed closed to plants because they put out so little light.

 

[f-e]

There's another thing that folks argue about. I always heard that if the plants had their leafs up it meant they were happy.. but it does seem to make sense that if they were getting too much light, that they would alter the angle away from the incoming sun.

I remember an old post from Coot ( I think it was in the ROLS thread, where he was asking about the leaves praying after an application of something...( I think it was aloe and silica?) He said it lasted for days. What would this mean? That the application caused the plant to be more sensitive to light?
Does anyone dim down their lights or raise raise their lights when they see praying leaves? What happens? How long does it take for leaves to flatten back out?

Well I went 450w to 550 and a few hours later looked back to see disaster. So back to 500w and the bulk of the canopy was fine, with just the main heads closing up a bit. With this balance of some open, some closed, I proceeded to use co2 regulation to open and close them. Yes, 600ppm had them looking happy and 400ppm rather reluctant to spread out.

450 to 550 is over 25% more and a striking change you wouldn't want. Just 5% increments should be noticeable. With 200ppm making a similar difference.

Tea-light candle. Just one. With enough extract to keep the RH in check with a full meter of canopy

Didn't see this topic going here.
You can buy a co2 meter with temp and RH showing, along with vocs (the smell) and a perhaps useless related measurement all on the screen together. Just £25 delivered from Ali. I picked one up for the hell of it. Though I'm actually using a controller to measure with, that has co2 temp and RH displayed. That sort of thing is starting to datalog now for £50. All this sort of stuff is really quite cheap. At £25 I'm hopeful it will sniff my exhaust and give me carbon life expectancy after a few years learning

 

[Loc Dog]

f-e -

What are signs of too much light???

 

[Gaussamer]

It doesn't bend because of gravity, it bends due to the same principles as a rainbow splits its light.

You seem like a cool dude, but it does NOT bend. It refracts. If you're going to get on people's case for being accurate, well, it goes around.

 

[flylowgethigh]

Well I went 450w to 550 and a few hours later looked back to see disaster. So back to 500w and the bulk of the canopy was fine, with just the main heads closing up a bit. With this balance of some open, some closed, I proceeded to use co2 regulation to open and close them. Yes, 600ppm had them looking happy and 400ppm rather reluctant to spread out.

450 to 550 is over 25% more and a striking change you wouldn't want. Just 5% increments should be noticeable. With 200ppm making a similar difference.

Tea-light candle. Just one. With enough extract to keep the RH in check with a full meter of canopy

Didn't see this topic going here.
You can buy a co2 meter with temp and RH showing, along with vocs (the smell) and a perhaps useless related measurement all on the screen together. Just £25 delivered from Ali. I picked one up for the hell of it. Though I'm actually using a controller to measure with, that has co2 temp and RH displayed. That sort of thing is starting to datalog now for £50. All this sort of stuff is really quite cheap. At £25 I'm hopeful it will sniff my exhaust and give me carbon life expectancy after a few years learning

I have one of these for each tent.

https://www.amazon.com/Hydrofarm-Autopilot-Desktop-Monitor-Logger/dp/B01FYWU2IS/

 

[GMT]

You seem like a cool dude, but it does NOT bend. It refracts. If you're going to get on people's case for being accurate, well, it goes around.

Same effect. It doesn't continue in a straight line, it gets bent to differing degrees depending on its wavelength. Red is bent more than blue and so can only be seen when the sun is very low in the sky.

Not sure where you think that's wrong. If it is, post a link, I'll read it and hold my hands up. Its what I understand to be the principle at play. There again I'm not a science teacher.