Plexiglass pane?

So I've seen/read about a couple setups, where someone used a plexiglass pane just under their lights to control temperature and/or prevent physical burning. Is this a valid technique? Does the plexiglass (or other material) block too much of the light? I would imagine it helps make keeping the temps down in your flower area much easier too. Just vent the compartment you created with the plexiglass basically.

I'm just kicking around ideas for my next setup...thoughts?

wondering the same thing ... except maybe lexan ... there is some light loss but minimal what Im worried about is melting ... dragon can you link to where you have seen it done b4 please

oh yeah I cant find tempered glass at a store front either any suggestions on where to look other HD/lowes? Would regular glass work ok or would it shatter after they go out and cool down ... then mince the goods?

bump.................

Before you go wasting your money on that shit, you should probably be told that you don't want your bulb that close to the plants anyways. Any closer than 12" and my lucalux 600's will start bleaching leaves. Hps bulbs can put out more lumens than the sun (obviously I'm talking lumens in a given space, not total lumens)

But anyways, don't put your lights so close. That's the moral of the story

I work with CFLs, I keep them within 1-2" of the plant.

Doesn't it melt and go yellow?

You can't "work" with CFLs, you "play" with CFLs.

lol the problem is the plexiglass could create hot spots by redistributing the light and focusing it in certain areas and you wont get an even distribution of light. It probable wont melt but it will more than likely warp a bit causing even more uneven distribution of light. It could convex and act like magnifying glass but to a much lesser extreme. Same with glass. you dont know how its going to redistribute the light.

Buy or make a cooltube or vented hood.

legallyflying said:

You can't "work" with CFLs, you "play" with CFLs.

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Yeah but that inclues 'playing' with cuttings and seedlings surely?
IMO, CFLs have their uses.

I did it last year it worked pretty good. You can buy plexi at most farm stores.I have 400wt hps/mh bat wing style. I measuerd the size and cut the piece with a sharp utility knife. I then drilled holes in the reflector and the glass and used bolts with wing nuts to hold it on. I took my hose and taped it on one end and used another hose for exhaust on the other end it was afro engineered but worked good as the heat was being blwon out of the light. The plexi wasnt hot to the touch either so i was able to get right on the plants.

This is basically the same idea as an air cooled hood.. or cool tube.. seal the lights off from the rest of the room to control heat. It does work if done properly, but you do want to make sure the material you are using is not going to burn or melt in your grow room.. Ultimately I would just say get an air cooled hood.. But I have actually done this before with clear lexan in a small closet under a stairway.. and it did help keep the temp down considerably at plant level. Good luck!

cues said:

Yeah but that inclues 'playing' with cuttings and seedlings surely?
IMO, CFLs have their uses.

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True that. And for a newb like myself, they served quite well for my first PC grow! (I pulled down 63g! dried!) Gotta start somewhere

As for the plexiglass...sounds like it's an alternative for cooling small setups where a hood or tube aren't feasible. I'll cross that bridge once I get the new flowering cabinet wrapped up.

Anything the light passes through helps degrade or diminish it.

it will work but your going to get hot spots because the light will be redistributed. if your only using a 400w light your not going to be covering a large enough area to really notice though I guess.. It will work but be carful of hot spots.

Here is the scoop on plexiglass: It will absorb up to 8% of your light, and it has a melting point of 320F. I would NOT use it for anything but CFLs, and even then you need adequate ventilation. And as for warping, if it got close to melting it would sag down, causing more light dispersion, not magnification. My 42w cfls are sitting right on the plexi and have been for a week with no problems... BUT on the other hand if your exhaust fan should fail you may have problems... I am not sure how hot a cfl would get in an enclosed space with no air movement... But I have a feeling an HPS would melt that shit on your budskies if your fan failed... Someone correct me if I'm wrong.

I didnt have problems with any of those issues. I was using a 400w hps with a 6" inline duct fan blowing though the light compartment almost no heat was felt underneath. You must be carefull cutting plexiglass as it wil spiderweb if your not carefull. All of you make valid points and should be taken seriously.Now to light that bowl

Hmmm hadn't thought about light loss, is glass the same?

Somehow my point about not needing or wanting your lights that close to your plants was lost