Is light bleaching real?

I may sound naive or maybe I am missing something but I have been growing indoors for about 10 years. I have never used anything less than a 400w HID, have used 1000w, and I currently prefer 600w for flower. Exhaust and circulation have allowed me to keep my lights closer than 8 inches for the most part. (Usually 6 inches) I have never had anything "bleach." The only time I have had anything but green leaves was if the plant had a deficiency. Am I missing something? When I first learned of the inverse square law, I took it to heart and worked for the greatest efficiency. My thought process has always been that the sun is much more intense than my HIDs. ?????? I have never even heard of this until RIU. Thanks for the answers guys. I am truly curious.

My understanding is that bleaching occurs when the leaf has used as much light as it could. The cells in the leaves are only able to use as much light as it can use for photosynthesis. After they are saturated, the remaining light is unused. It can't be used in photosynthesis, the plant is "full" of light and can't take in anymore. Like a wet sponge. Additional light past this point can damage plant cells causing bleaching, browning and stunted growth.

Think of it like this...You can only breath as much oxygen as your lungs can hold. Even if you took in more oxygen, your body can only absorb so much. After than, oxygen becomes toxic. It damages cells and can kill you.

Might be less from intensity and more from exposure. So keeping plants under intense light in an 18/6 growth cycle may not cause damage, a continuous 24 hour exposure may.

I stopped 24 hr veg light after reading articles online about light saturation.

Makes sense now...thank you.

Yes it's real bro. A plant can only take so much light. Yes more light is better but that's only to an extent.

How would you like it if someone stuck your face right next to the sun?

giggles26 said:

Yes it's real bro. A plant can only take so much light. Yes more light is better but that's only to an extent.

How would you like it if someone stuck your face right next to the sun?

Click to expand...

Most people people I have seen have only linked the bleaching with lights being too close. But as I said, I keep mine as close as possible and never had an issue. But the plant only being able to use so much light, that makes sense. I guess I have just been lucky.