too late to raise my light? Mid flower

mobone

Well-Known Member
I'm abotu half way into flower and have realized my light is too close. It's a 150w about 6-8" away. It is possible to have too much light. A plant only wants and needs 10k lumens and if its getting more than that it wont grow any taller. I'd like it to get a little taller, but I'm in flower. I was wondering if you think I should leave it or raise it.
Thanks.
 

Drio

Well-Known Member
I have never seen a grow go wrong from to much light.

Rather , - the plants are unable to cope with the heat that comes from being close to the lights.

With good cooling tubes or sun systems that cool the bulp you are free to put it as close you wish.

Just as long as it doesn't burn them from heat.

---

There is one thing that should be acknowledged though ,- and that is that the more light you have , the more growth the plant can handle.

If you remove light restrictions and give her all she could ever wish she will be limited by something else , possibly a deficiency that never was a problem before the lighting brought the growth speed up.
 

mobone

Well-Known Member
It just seems like they're slowing growth. Can't pin point why. Temps were a little high and raising the light did decrease the temps, but I raised it a lot. It's over a foot away now. I don't want to stress them in this crucial time.
 

StreetRider

Active Member
IF you were able to veg at a sertian height you should be able to flower at that distance. Just keep air flowing and you will be great.

It is the high temps that slow the growth. If you think about it. If your room is at 80 right under the light it is much hotter. Think of being out in the direct sun. It always feels hotter.
 

sandmonkey

Well-Known Member
I have never seen a grow go wrong from to much light.
Sorry, but I can't disagree more. There is such a thing as light bleaching which occurs when lights are too close; especially with HID's.

I've experienced it during my first grow. Here's a pic (not mine) of what light bleaching looks like. Doesn't look anything like heat stress:

 

StreetRider

Active Member
I stand corrected. You can bleach them.. And once bleached they do not gather energy. You are correct, and I did it myself. But that was with a 600 Watt less then a foot from the tops.

You are correct sir.

Most people have the other problem thou. They keep the light way high looking for growth. But, that is stretch.
 

sandmonkey

Well-Known Member
You're right. People (myself included) worry about stretching so they place the lights way too close to the tops. One of my NLX plants got bleached by my 400w HPS during the last 2 weeks of flowering, so the effects weren't really felt.

However I just did the same with one of my Warlocks in veg, and with a CFL! it's barely visible though so I'm not worried.

Point is, there is such a thing as too much lights; even if they don't put out much heat.
 

mobone

Well-Known Member
Is this bleaching, or nute burn. I guess my main question in this thread is: will the plant grow taller, in search of more light, in flower stage if I move the light away.
 

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Drio

Well-Known Member
Give the girl a very good flush and equalize the PH.

Then give her some fresh nutrients.

-_-

Again , light is never bad.

If the light is emitting excess heat that could hurt the plant , move it up a bit.

Ive seen varius guides that point to light bleaching but my plants have licked the cooltube of my 600w hps and never get scarred by them.

I have on the other hand experienced light burns from foilar reflections.

Those could happen.

Regardless , most of the pictures ive seen of the "alleged" light bleach were obvious deficiencies or heat problems.
 

StreetRider

Active Member
I agree that could be a deficiency, but I also beleive that light bleaching does happen. Tender plands can be bleached. Maybe some strains are more prone.

If you are not using a light meter <edit - temperature probe> use the back of the hand method and you will be fine.

And remember kids... Streching is not good growth.
 

mobone

Well-Known Member
I do have more than 75w per square foot. How far away do you think I should keep my 150w hps away. I just go off this chart, and put it at 8", but should I put them higher due to my small sq footage? It's only about 1.3 sq ft.
 
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