Never Too Much Light

Situation: I have a few 400wt hps in my flower room. They are enclosed and cooled. A person can touch the glass and are moderately warm to the touch.

Question: As long as there is no heat coming off of the glass, is it safe to let the ladies grow right up to the glass? This would put them roughly 4inches away from the actual bulb where they'll be getting a wonderful amount of light, cool to the touch even.

I had read in Jorge's book that you can never have too much light. In my thinking, letting them grow clear to the glass covering the hood should pose no problem as long as there is no heat issues.

Wrong or Right?

as long as the bulbs are not hot then it should be the same as a CFL in respect to the plants being able to touch the bulbs. I personally would cover the open area where the bulb is with a mesh so the plants dont grow into an area that can cause a fire. Just monitor the plants the closer they get to the light, just in case they do decide to burn.

GG23:jointsmile:

I agree with Jorge and GrowinGreen... as long as it's properly cooled, you can never have too much light, but there might be areas that are warmer than others on the hoods and while it may not be hot enough to start a fire, it might scorch the tops of the plants. I start to move my lights up incrementally once the leaves are actually touching the glass, but only by an inch or so each time so that the lights are still as close as I can possibly get them.

Great, thanks for the info. I have been doing as Clandestine is doing. They grow to the glass and I bump the light up about 1-2 inches.

I took a temperature reading right from the glass and the glass itself was 85F. I don't feel in danger of burning anything at that low level.

i would have to disagree. there is no reason to do something like that. the differance in light between the glass and the lower part would be obstructed further by letting your plants crown the fixture not beneficial enough to the canopy to justify starving the lower canopy. imo. and safety should come first both for you and your crop. 85% isnt bad but i think it will affect your plants negativly in the long run. in nature the sun ever comes in contact with any vegatation right? i believe it is the image reaper who says "when in doubt imitate nature" this technique would be a contradiction to this tried and true method. sorry for ranting. i guess what im saying is i wouldnt do it.

-secret:)

I don't see any problem with the method of moving the light up as the plant gets within a certain distance... If it's as cool as you describe, they should be fine as long as none of them are actually in contact with the glass...

but that what hes talking about is letting them grow right up and touch the glass.

-secret:)

I had thought that shading would be an issue as well, but given the way the room and other lights are arranged, even the lower branches are getting ample light. This would have to be something each grower would have to determine based on their setup.
As long as the rest of the plant is getting light, letting it grow to the glass is no more or less artificial and imitative of mother nature than the act of growing a plant under lights.

The plant doesn't know if it's 10" or 1" away from the bulb. It knows how much heat it has and now many lumens etc.

I posted this pic in another thread the other day. I think it fits in here.

As long as the glass isn't hot, there shouldn't be any burning. You do open the door to some funkiness, though. :)

This bud was positioned as mentioned by the OP. The pistils were just grazing the glass, directly below the bulb. (400HPS)

Looks odd, but that's about it.

Quote:

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Originally Posted by EvilCartman

I posted this pic in another thread the other day. I think it fits in here.

As long as the glass isn't hot, there shouldn't be any burning. You do open the door to some funkiness, though. :)

This bud was positioned as mentioned by the OP. The pistils were just grazing the glass, directly below the bulb. (400HPS)

Looks odd, but that's about it.

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That's a funky looking plant! I've never seen the leaves turn white like that..lol

Quote:

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Originally Posted by secret420

but that what hes talking about is letting them grow right up and touch the glass.

-secret:)

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Ah yes - well then I have to agree with your comment secret420. The situation reminds me of when my house-plants on the window-sill are touching the window and can eventually stick to it in an adverse way. Probably not hurting anything, but definitely not natural and not worth the risk - better to keep at least an inch away at all times would be my opinion... :thumbsup:

Let me restate the condition.

The tops get to touch the glass, there is no pressing up against it. When the tops touch the glass, I slide the lights up an inch or two.

its fine to do this,as far as not shedding enough light 2 the lower branches i say screw it your biggest yield will be derived from your main colas anyways.its safe but i would say 85 is a little warm.personally i would keep them just a few inches from the top of the canopy and that will also encourage them to continue growing in heigth because they still have somethng to try and reach 2.

i gotcha, as long as you move them when they get there. sorry for the confusion.

-secret:)

hahaha that pic from evil cartmen looks wild! (by wild i mean cool)

-secret:)

I thought that I had read in Jorge's Bible that you want to keep the light about 12 inches away from your plant. Even if you are at 12 inches then you would be getting some great lumens anyways. Your bulbs rating is taken at 12 inches from its glass. So my 600 has like 90k lumens and thats measured at 12 inches. I dont know about you guys but I am not that greedy lol, I am with secret on this one. I think that lower portion would not like the loss in light.

I'm such a tool. Somewhere I got the measurement that the light should be 18 to 24 inches. I'm like on the roof at this point. Tonight I saw a chart that suggests that up to 5 inches was ok and actually best. Now I see this thread and I'm wondering why I'm 30+ inches away??? I have an air cooled hood with blower and fans. My temps are always in the 70's and my hood is so cool that I have no fear resting all kinds of stuff on it. Tonight I lowered it to 12" but I think by the end of the day I will put it even closer. According to the chart I read, each inch of distance was 10k lumen loss and at 30 inches, there was practically no light at all. I'm disgusted with myself...no wonder my plants wont grow for shit.

I'm very pleased to learn this information. There can never be too much light...just too much heat. So as long as the heat is kept under control, then I can put the light up the plants azz for all it cares.

I ended up raising my lights. Ya they're covered and have excellent air cooling but as it flowers more and more, the tops and the next row of leaves really do shade the heck out of the 3rd and 4th row of buds. So now I've got them about 10" away and things seem more well lit. I think if you were only using one plant per light, which I did in an experiment, it is a great thing to let them go up to 2" from a cooled hood. That plant is actually my best producer so far. But it's a waste of light.

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http://boards.cannabis.com/members/m...37-pic0046.jpghttp://boards.cannabis.com/members/m...38-pic0047.jpghttp://boards.cannabis.com/members/m...39-pic0059.jpg
You know what that is? It's not "too much light" because that doesn't even exist but a burnt leaf. Instead of burning to brown it stood white as it's visible just like yours.
Sorry I don't know how to put thumbs to this forum's album.