Never Too Much Light

[RoundEye]

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?

RoundEye Reviewed by RoundEye on 10-28-2009. 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 Rating: 5

[GrowinGreen23]

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:

[Mr. Clandestine]

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.

[RoundEye]

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.

[secret420]

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

[Dayzt1]

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...

[secret420]

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

-secret

[RoundEye]

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.

[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.

[Dayzt1]

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.

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