Maximum lux, when is too much light

[Frankster]

80-85,000 lux, too much?

one of my taller main cola's is getting around 120,000 lux right now, is that too much?

 

[Frankster]

Hmm, looking at different types of LED burning, this has never been an issue for me before, but with these new lights, it appears that is most certainly can be. highering these lights too compensate, that's probably been the source of my mysterious "nutrient" problems, it appears.

Learn something new everyday, now I know what it looks like.

 

[Frankster]

Glad I put my finger on this before it got too bad. Anyone with experience with this sort of thing, please clarify if I'm correct, I could use some affirmation on this one.

Here's the pics.

 

[MIMedGrower]

Hmm, looking at different types of LED burning, this has never been an issue for me before, but with these new lights, it appears that is most certainly can be. highering these lights too compensate, that's probably been the source of my mysterious "nutrient" problems, it appears.

Learn something new everyday, now I know what it looks like.

Of course i have no led experience so hopefully someone will chime in that does but i have read in the builder and hlg threads at another site that too low temperature is the cause of the bad magnesium/ calcium uptake. With little radiant heat from the lamps temps need to be higher to compensate.

 

[Greenjourneyman]

It sounds like your pumping a lot of light. I’ve always assumed that over 90k in lumens was a diminishing return.
I don’t see any of the white spotting or bleaching though most commonly associated with light poison.
your choice dim it back some or keep trucking. If things go bad you’ll notice.

 

[One drop]

It sounds like your pumping a lot of light. I’ve always assumed that over 90k in lumens was a diminishing return.
I don’t see any of the white spotting or bleaching though most commonly associated with light poison.
your choice dim it back some or keep trucking. If things go bad you’ll notice.

45 to 65 k is more than enough Frankster I run 5 to 7 seedling clone , 15 to 50 veg plants 45 to 65 k is where I run mine gives you better chance to get you VPD right .

 

[CF89]

 

[JWM2]

Glad I put my finger on this before it got too bad. Anyone with experience with this sort of thing, please clarify if I'm correct, I could use some affirmation on this one.

Here's the pics.

Light burn from LEDs is absolutely an issue. I battled it for months thinking it was something else. Temps and VPD were spot on and still had the issues you’re seeing. Turning down the lights fixed it. I bought a cheap lux meter and made a chart so I know whereabouts I need to be. As the plants get taller you need to lower the light intensity by turning them down or raising the light.

 

[Milson]

Depends on the light/spectrum, but I have found with my lights I start seeing stress when I go much over 60k at canopy height even with a mature plant.

 

[Milson]

You can convert Lux to PPFD with a simple multiplier. This isn't complicated. It's just finding that multiplier for your particular spectrum is prohibitively difficult for most growers. But the point is, one exists. So if you have a consistent lux meter you can credibly use lux for your situation (comparing light intensities to plant reaction) and it will work just fine. It is true you should not use lux comparisons between lights due to the spectrum difference.

I know you can convert lux to ppfd with a simple multiplier by chasing down papers from I believe here: https://www.waveformlighting.com/horticulture/convert-lux-to-ppfd-online-calculator or here https://www.researchgate.net/profile/Mohammad_Reza_Malekzadeh/post/how_can_I_convert_light_intensity_in_lux_to_micro_moles_per_square_meter_per_second_of_PAR/attachment/5df92d86cfe4a777d4fba68e/AS:837182231166976@1576611206465/download/Greenbeams+PPFD+Conversion+Tables_0.pdf