Is Light Bleaching real or bull Shit?

motul123 · Feb 11, 2012

I have seen a few reads about light bleaching but half say its a myth and half say its real?. Anyone have pics of this or experience?

rollinbud · Feb 11, 2012

my hair bleaches out in the summer to blonde so why not marijuana. I would say definitely yes if your light is too intense and temps. warm.

researchkitty · Feb 11, 2012

Our grow op has about 14000 to 18000 watts of flowering at any given time............. Sometimes, if a plant gets too close to the 1000w hps lamps, it will bleach the hairs out, turn it pretty white, and then if uncorrected, continue to hurt the plant.

Brick Top · Feb 11, 2012

motul123 said:
I have seen a few reads about light bleaching but half say its a myth and half say its real?. Anyone have pics of this or experience?

It's real.

motul123 · Feb 11, 2012

I ask cuz I think I might have one. It looks healthy but the new leaves are bleaching a bit. Here is a pic. The rest of the plants look good, though I do have a Ice that has a little yellowing on the edge of one leaf, also will include a pic. Whats your thoughts. Also I have started a 1/4 nute feeding after 3 weeks growth all organic HESI. The problem was there before the nute sched.

Detroit J420 · Feb 11, 2012

sure can bleach the hairs and the leaves.... ive done it with hid, and l.e.d, as long as the temps arent to bad potency should still be good

Phaeton · Feb 11, 2012

When the light (not heat) bleaches a plant it just destroys the chlorophyll. The affected parts turn white, but the leaf itself still respirates and is not dry or crumbly. Usually heat is involved and the leaf will dry out, but straight light overload only kills off the chlorophyll to start with.

researchkitty · Feb 11, 2012

You generally wont light bleach your vegging plants, or plants without flowers on them. Instead, those plants get nasty and crumbly and dry then die. But for the mid to end of flower if the plants grow too tall into the lights and tha tisnt controlled, is when the light bleaching generally occurs......

2poodles · Feb 12, 2012

Absolutely. I wish I wouldn't have thrown away a leaf that was almost white.

a666as · Mar 18, 2012

hi guys, i know this is an old post, but just wanted to show some pics of what i believe is bleaching. I've been giving a good dose of nutes and so ruled out any defs. the plants have grown pretty tall and the distance from my 400w hps is about 12 inches, but thats the furthest it can be in my growbox. I would think there is some harm with having the chlorophyll burnt out of your leaf...just

not sure how much though

girls just finished week 7

outlander1 · Mar 18, 2012

Not bleaching, just your plant eating up needed nutrients (N) present in your leaves. You are in late flowering and this is expected.
On the home stretch!

bigv1976 · Mar 18, 2012

I am not sure on this. They say the sun is brighter than any light you can buy for growing so wouldnt it make sense that outdoor grows would bleach if it was a fact?

Rj41 · Mar 18, 2012

Under artificial lighting, it is a real thing.
I don't remember all the details, but it has something to do with number of foot candles of light reaching the plants.

Bricktop; any chance you could jump back in and explain it better?

ChrisGGG · Mar 18, 2012

I think this was bleaching among other things. The top was 3" from 250W HPS.

ValleGrown · Mar 19, 2012

Rj41 said:
Under artificial lighting, it is a real thing.
I don't remember all the details, but it has something to do with number of foot candles of light reaching the plants.

Bricktop; any chance you could jump back in and explain it better?

You could just as easily research this yourself and post it as he does.

ValleGrown · Mar 19, 2012

Not saying that bricktop doesn't know his shit but.. Still. He's not your monkey

Happy growing

missnu · Mar 19, 2012

the concentration of the sun outside is spread out over everything and there are usually other things in the way...when a plant is growing inside under a light the light is concentrated, but I think a lot of times what people want to call light bleaching is actually just some other issue...I haven't seen any pics yet that were lgith bleached...and a lot of plants can get bleached while others can't...MJ is hard to bleach as it prefers full sun and is set up to deal with ultra bright lights...but plants that like shade or partial sun can bleach in a heartbeat.

ValleGrown · Mar 19, 2012

missnu said:
the concentration of the sun outside is spread out over everything and there are usually other things in the way...when a plant is growing inside under a light the light is concentrated, but I think a lot of times what people want to call light bleaching is actually just some other issue...I haven't seen any pics yet that were lgith bleached...and a lot of plants can get bleached while others can't...MJ is hard to bleach as it prefers full sun and is set up to deal with ultra bright lights...but plants that like shade or partial sun can bleach in a heartbeat.

I actually don't think this is entirely true. MJ I believe gets stressed out after about 16 hours of light. They get tired from working. They need rest. They don't get light 24/7 or even 18/6 anywhere on this eart that are suitable growing conditions. Even in afghanistan or the Mexican landrace sativas don't get that much light. They get shaded by clouds and things trees etc.. But just thought I would say that you must mimick nature. In a grow tent with 50k + lumens that's no where near nature. You figure on the best days x amount of lumens per square foot is good. The sun is powerful enough to have exceptional penetration through the canopy to spread out in the lower levels of the plant but with the best hid lights you have maybe 2' of penetration to the canopy . So as the light separates you loose lumens. And growing power. People have learned to correct this by lowering their lights. HID lights can bleach plants if left for hours on end with extreme exposure to the canopy within inches of the bulb. That powerful Of a spectrum for that long. With that amount of lumens so close will definitely damage the pigment of any living thing.

ValleGrown · Mar 19, 2012

So I do Apologize sir but your claim of full sun is not entirely accurate.

ValleGrown · Mar 19, 2012

ValleGrown said:
I actually don't think this is entirely true. MJ I believe gets stressed out after about 16 hours of light. They get tired from working. They need rest. They don't get light 24/7 or even 18/6 anywhere on this eart that are suitable growing conditions. Even in afghanistan or the Mexican landrace sativas don't get that much light. They get shaded by clouds and things trees etc.. But just thought I would say that you must mimick nature. In a grow tent with 50k + lumens that's no where near nature. You figure on the best days x amount of lumens per square foot is good. The sun is powerful enough to have exceptional penetration through the canopy to spread out in the lower levels of the plant but with the best hid lights you have maybe 2' of penetration to the canopy . So as the light separates you loose lumens. And growing power. People have learned to correct this by lowering their lights. HID lights can bleach plants if left for hours on end with extreme exposure to the canopy within inches of the bulb. That powerful Of a spectrum for that long. With that amount of lumens so close will definitely damage the pigment of any living thing.

University of Minnesota proved this I believe when they brought you G-13.

Is Light Bleaching real or bull Shit?

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