Having A Light Source Too Close

[DrPhoton]

I seen the thread you are talking about on autoflower.net

[DrPhoton]

You can buy just the PAR sensors and connect them to a multimeter. Cheap and effective hack. There are some tutorials on youtube i think.

[DrPhoton]

Thats fine, i wonder if you just hyperlinked it to here though so if there are any questions i can address them. No doubt people will argue points but not everyone understands it.

[roperman]

If only someone invented a way to measure the light on the canopy without an expensive PAR meter. Is there any way to gauge the light without one? A way to measure 500 umols using some hack? I would love to see some sort of "sensor" paper. You put the sheet of paper on the canopy for 10 minutes, remove, and check the color. Just like pH strips.

[Vapo69]

Hello Dan......Do you mind if I rip your article and post it on another forum.....its pertinent to what I said on there.....thanks Dan.......I wont post until you reply

[DrPhoton]

Glad it helped

[jerry]

Some great info in this thread! Glad to know more about this now, I learned the hard way with keeping lots of extra distance for LED lights. Another benefit is the extra height will help give a little "safety room" during the stretch!

[DrPhoton]

Exactly, thats what i was hoping would be interpreted. A plant may thrive with the "back off slightly after symptoms" method. But you could be holding back up to one third of usable energy that goes to waste. Of course you have to balance between good light placement and plant health. Because you can just as easily loose that much energy from having your light source too high.

Happy learning.

[KingKush]

So "lights close as you can till you see a negative reaction and then back off slightly" is actually flawed thinking?

Psh it's tough to admit you are wrong sometimes but you have inspired me to swallow my pride.
I have to agree that if a plant is using resources to make a defensive reaction it will not be making headway towards botanical excellence.
So the tops of my Kush are starting to be veggie with thick dark twisted leaves coming out of the bud. But just where it's riding the line. I raised my lights about 3" today. Immediately afterwards they stink vs. yesterday they didn't, just one observation.

Thanks Danofdanger for sharing. Keep it up.

[DrPhoton]

Omitted for easier readability and further information.

[DrPhoton]

My pleasure, happy learning.

[Vapo69]

Dude..Thank you..........much appreciate the reading material, I'm going to tackle it soon

[DrPhoton]

Vapor Pressure Deficit is the potential for water in leaves to move from a high humidity environment to a low humidity environment. Think of it like a towl drying on the cloths line. The towl is the leaves. Saturated in water. Gases and liquids want to move from high concentration to low concentration, which is what happens with the towl when it drys on the line. So the same thing happens with leaves and so moisture is vented out and creates water movement in the leaves and the entire plant because of the hydrogen bonds causing cohesion. So the movement of water is a completely passive process. Where as the movement of sap is partly active.

[DrPhoton]

Here you go.

[Vapo69]

Also I have searched Amazon for the book "Light measurement handbook." By Alex Ryer but cannot find it??