Can Your Lights Be Too Bright?

[Delps8]

Girl Scout Cookies photo, three and half self watering pot, Updayday LED 700W. Oh two and half months old getting ready to flip.

One plant acts like it was getting too bright a light. Leaves curling.

I turned the light down and my Son moved the plants around

When the leaves curl, you're at the light saturation point for the plant so turn the dimmer down a few % and your plant will be "well fed".

How quickly did they uncurl?

 

[Blue_Focus]

This was from my light being to bright. The leaves was drooping too.

Since I turned down my light they're happy again.

 

[amneziaHaze]

Get a ppfd phone app turn to lux
Quick Guide – Lux Levels for Optimal Cannabis Growth

Life StageMaximumGoodMinimumVegetative70,000 lux40,000 lux15,000 luxFlowering85,000 lux60,000 lux35,000 lux

< 15,000 lux – sparse or “stretchy” growth – plant isn’t getting enough light
15,000 – 50,000 lux – a good amount of light for healthy vegetative growth
45,000 – 70,000 lux – the optimal amount of light for cannabis plants in the flowering (budding) stage. If grow lights produce a lot of UV light (such as LEC), stay on the lower side of this range
70,000 – 85,000 lux – a lot of light, some strains thrive at this light level, but some plants (especially auto-flowering and Indica strains) lose their top leaves early under this light intensity. At these levels, lights need to be kept further away for healthy growth
> 85,000 lux – at this light intensity, you’ve hit the plant’s “saturation point” which means your plant can’t use all the light (most strains will experience light bleaching or other major signs of stress at this level!)

 

[Rocket Soul]

This was from my light being to bright. The leaves was drooping too.

Since I turned down my light they're happy again.

That type of deficiency could be either too intense light in current environment or too weak nutes.

From research it seems very hard to hit the absolute too much light level with any growlight we use around here, but you may have a limiting environment or just too little nutes.

 

[Oldguyrealy]

That type of deficiency could be either too intense light in current environment or too weak nutes.

From research it seems very hard to hit the absolute too much light level with any growlight we use around here, but you may have a limiting environment or just too little nutes.

Only have one plant doing it.

As far as Nutes I mix Rainbow Pro Mix Grow into the soil when I mix it along with lime and Wood Ash.

Then when I flip I use Rainbow Pro Mix Bloom. This time lime and Worm Castings.

Going to start mixing Worm Castings in on first mix.

Did one Grow and it was the best I ever had.

I use this mix on all my plants and they are doing good.

 

[SouthFloridaGenetics]

I've got 2240W of light over a 3 x 10 area. The LUX is 76k-80k across the entire area. The plants love it. There are 3 Sweet Tooth, 1 Vanilla Velvet, and 1 Fruity Fun.

 

[Rocket Soul]

Only have one plant doing it.

As far as Nutes I mix Rainbow Pro Mix Grow into the soil when I mix it along with lime and Wood Ash.

Then when I flip I use Rainbow Pro Mix Bloom. This time lime and Worm Castings.

Going to start mixing Worm Castings in on first mix.

Did one Grow and it was the best I ever had.

I use this mix on all my plants and they are doing good.

Your flower nutes, are they also in the soil slow release? That may the problem.
The way we deal with these issues is by measuring ec and ph of the runoff. If EC comes out low then just up the nutes.

As a general advice id rec using liquid hydro nutes for led grows and if not, at least have some calmag in your waterings.

 

[jimihendrix1]

At the equator, the sun’s intensity gives us a Photosynthetic Photon Flux (PPF) of 2000 µmol/m 2 /sec of light, which is roughly equivalent to 10,200 foot candles or 108,000 lux.

IMHO, the limiting factor, for indoor gardening, especially in a tent, is fresh air exchange. Outside, the PPM of Co2 aint that high vs supplementation, indoors of 1000+ PPM. Outside is what?? 420 PPM?
Thing is, outside, there is a never ending, constant Fresh Air/Oxygen/CO2 exchange, of which the plants will never be able to utilize all of it. Indoors, the air exchange is really hard to equal outside conditions, but is simple, to have huge amounts of PPF available, because of the light tech. Either LED, or HID.
I also agree, some strains may not do well, with high amounts of PPF. But, at the same time, they may do well with higher amounts of UVA/B supplementation, as many broad leaf afghanis may not be from the Equator, but they are mostly from higher altitude, which I believe there is a 10% increase in UVA/B, for every 1000ft in altitude.
Normal UVA/B reading that the weather forecasts give, have a rating of 1-10. At 20,000ft altitude, in Ecuador, a UVA reading was given a 42-43 rating!!! Higher than on Mars!!! Of course nothing grows there, but goes to show you, higher altitudes, have a huge influence on UVA/B. I also believe. some plants may also not do well with higher UVA/B either. If the genes didnt originate from areas with high UVA/B. And, if one uses hybrids, such as possibly one parent not having a need for high PPF, and the other loving high light levels. Then, you will have some plants that thrive on lower light conditions, and others, one the other end of the scale, and others in the middle. So in a pack of seeds, you may burn some plats up with high PPF, and others may not like lower PPF. And those in the middle. Including males of course.
I do believe narrow leaf, long flowering varieties-12-25 weeks, do much better under really high light levels.
I also start seedlings under high light levels. Ive used 1000w HID, since 1977, when they first came out, to start seeds. I figure, Outside, they get blasted, from day one, so it just makes sense, to me, to do the same, inside. I also like grow temps, in the mid 80s. 83f-87f.

To me, its as simple as, if one has really high amounts of light, one must also have really high amounts of fresh air exchange. They go hand in hand, and there is no compromise.

 

[Rocket Soul]

At the equator, the sun’s intensity gives us a Photosynthetic Photon Flux (PPF) of 2000 µmol/m 2 /sec of light, which is roughly equivalent to 10,200 foot candles or 108,000 lux.

IMHO, the limiting factor, for indoor gardening, especially in a tent, is fresh air exchange. Outside, the PPM of Co2 aint that high vs supplementation, indoors of 1000+ PPM. Outside is what?? 420 PPM?
Thing is, outside, there is a never ending, constant Fresh Air/Oxygen/CO2 exchange, of which the plants will never be able to utilize all of it. Indoors, the air exchange is really hard to equal outside conditions, but is simple, to have huge amounts of PPF available, because of the light tech. Either LED, or HID.
I also agree, some strains may not do well, with high amounts of PPF. But, at the same time, they may do well with higher amounts of UVA/B supplementation, as many broad leaf afghanis may not be from the Equator, but they are mostly from higher altitude, which I believe there is a 10% increase in UVA/B, for every 1000ft in altitude.
Normal UVA/B reading that the weather forecasts give, have a rating of 1-10. At 20,000ft altitude, in Ecuador, a UVA reading was given a 42-43 rating!!! Higher than on Mars!!! Of course nothing grows there, but goes to show you, higher altitudes, have a huge influence on UVA/B. I also believe. some plants may also not do well with higher UVA/B either. If the genes didnt originate from areas with high UVA/B. And, if one uses hybrids, such as possibly one parent not having a need for high PPF, and the other loving high light levels. Then, you will have some plants that thrive on lower light conditions, and others, one the other end of the scale, and others in the middle. So in a pack of seeds, you may burn some plats up with high PPF, and others may not like lower PPF. And those in the middle. Including males of course.
I do believe narrow leaf, long flowering varieties-12-25 weeks, do much better under really high light levels.
I also start seedlings under high light levels. Ive used 1000w HID, since 1977, when they first came out, to start seeds. I figure, Outside, they get blasted, from day one, so it just makes sense, to me, to do the same, inside. I also like grow temps, in the mid 80s. 83f-87f.

To me, its as simple as, if one has really high amounts of light, one must also have really high amounts of fresh air exchange. They go hand in hand, and there is no compromise.

CO2 is of course also very important for photosynthesis. But in this case, where theres some clear signs of nutrient defs, i would not think CO2 would be the culprit. Afaik theres no deficiency signs of low co2, only slower growth.
If you think about it: the nutes we give dont really have a direct role in photosynthesis which is just co2 + h20+ light > o2 +sugars, which consists of carbon, oxygen and hydrogen, theres no NPK in that process.

 

[SouthFloridaGenetics]

CO2 is of course also very important for photosynthesis. But in this case, where theres some clear signs of nutrient defs, i would not think CO2 would be the culprit. Afaik theres no deficiency signs of low co2, only slower growth.
If you think about it: the nutes we give dont really have a direct role in photosynthesis which is just co2 + h20+ light > o2 +sugars, which consists of carbon, oxygen and hydrogen, theres no NPK in that process.

Here are some nice material to help visualize the relationship between photosynthesis and respiration. Enjoy!

 

[Oldguyrealy]

Your flower nutes, are they also in the soil slow release? That may the problem.
The way we deal with these issues is by measuring ec and ph of the runoff. If EC comes out low then just up the nutes.

As a general advice id rec using liquid hydro nutes for led grows and if not, at least have some calmag in your waterings.

Ok thanks!

I only feed twice, have no run off and don't PH my water.

 

[jimihendrix1]

Here are some nice material to help visualize the relationship between photosynthesis and respiration. Enjoy!

Nutrients have a direct role by giving the plant everything to function properly. Without at least some sort of nutrients, it dies. No more photosynthesis. If all nutritional needs are met, theoretically, all metabolic process should be working near 100% efficiency.
Food allows the plant to live, to be able to do photosynthesis. It all works together.

 

[Oldguyrealy]

Nutrients have a direct role by giving the plant everything to function properly. Without at least some sort of nutrients, it dies. No more photosynthesis. If all nutritional needs are met, theoretically, all metabolic process should be working near 100% efficiency.
Food allows the plant to live, to be able to do photosynthesis. It all works together.

Well give them Rainbow Pro Mix nutes and Compost and Top Soil.

All my plants are doing well except for this one. I've had trouble with this light before.

 

[jimihendrix1]

Well give them Rainbow Pro Mix nutes and Compost and Top Soil.

All my plants are doing well except for this one. I've had trouble with this light before.

I wasnt addressing the plant health ect.

I was addressing the original question about... Can the Light Be Too Bright. Which, yes, it can, depending on environmental conditions.

Theoretically, if one can achieve 2000umol and 108000 LUX in any given area, and an unrestricted airflow, one could be close to approximating the sun. Not to mention the correct spectrum.

Im also a fan of Promix Products. I use Promix BX Medium.

 

[Blue_Focus]

That type of deficiency could be either too intense light in current environment or too weak nutes.

From research it seems very hard to hit the absolute too much light level with any growlight we use around here, but you may have a limiting environment or just too little nutes.

It was the light. It's growing like a weed now and it's happy.

My WiFi camera makes it look lighter than it is.

 

[Rocket Soul]

It was the light. It's growing like a weed now and it's happy.

My WiFi camera makes it look lighter than it is.

Id try giving it just a tad bit more nutes, my 2cts. Too me too much light and too little nutes is pretty much the same thing.