Grow light glass. keep it in or take it out?

over the years, i've read this and that about having a glass cover on your grow light.

i didn't use one for years but i've been using one that came with my sun light grow light for the last couple of years for no particular reason. i don't have a heat problem so i think i might take it out if indeed it will increase the UV reaching the plants.




do you keep the glass your unit came with in or take it out?

depends on how ur setup is. co2, aircooled, passive intake or forced, light size, sealed, airconditioned,? plus some other variables.

im forced intake with dust shroom, with forced exhaust in a sealed aircooled hood ran to a carbon filter.

wheels619 said:

depends on how ur setup is. co2, aircooled, passive intake or forced, light size, sealed, airconditioned,? plus some other variables.

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it's just a nice simple set up. a tent in a spare room. i never close the tent up. the room is around 72 degrees before lights on and about 80 at lights out.


i'm just curious how many people take the glass out.

i dont think anyone does they get the cooled hood to keep it cooled, dont want glass get a adjust-a-wing, if u think ur temps will be fine then go for it it is just gonna let a lil more light through

i guess i wasn't as clear as i could have been.

i wanted to know if people kept the glass in or not.

i'm not trying to figure out if i should take mine out. i just took it out.

what size light? if its small under a 400 go for it. take it out. if its big the glass isnt going to stop much.

He's talking the UV blocking barrier glass on MH. You remove it the last 2 weeks of flowering to increase THC production.

if HID did not need aircooled i would or if my setup could handle the extra temps i would.

not so much for UV since HID bulbs are designed to prevent 100% of the UV we want from coming through.(280nm) and most of the UV we get is UVA which still has somewhat the same effects.

but even if i was not growing with glass between bulb and grow i would still supplement UVB with a MVB bulb

hotrodharley said:

He's talking the UV blocking barrier glass on MH. You remove it the last 2 weeks of flowering to increase THC production.

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polyarcturus said:

if HID did not need aircooled i would or if my setup could handle the extra temps i would.

not so much for UV since HID bulbs are designed to prevent 100% of the UV we want from coming through.(280nm) and most of the UV we get is UVA which still has somewhat the same effects.

but even if i was not growing with glass between bulb and grow i would still supplement UVB with a MVB bulb

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i found an old ask ed article. ed said to change out the HPS the last 2 weeks and use an MH. i might give it a go, as i'm very familiar with the genetics in flower. if i notice a difference, i'll be happy. if not, it's still great pot.

http://www.cannabisculture.com/node/10584

"Metal halide lamps emit more UV-B light than high-pressure sodium (HPS) lamps, so for more potent buds it is a good idea to use MH lamps the last 10 days of flowering. Air-cooled light reflectors have glass covers that absorb UV-B light. If it is feasible, remove it, so the light can shine unobstructed on the plants."

no, the outer envelope on a bulb(MH) has chemicals that prevent UVB from escaping. you will get similar effect as using from the MH, from 420nm and lower light from the MH but if you want frost... you need UVB to get that you need one of these three current options

MVB
http://www.joshsfrogs.com/exo-terra-solar-glo-160-watt.html?gclid=CIuS0bXYo7ICFcbrKgod3kUALg
CFL
http://www.joshsfrogs.com/lighting/uvb-producing-bulbs/spiral-compact-florescent/exo-terra-repti-glo-compact-26-watt-10-0.html
T5or t8ort12
http://www.joshsfrogs.com/exo-terra-repti-glo-10-0-desert-terrarium-lamp-48-inches-40-watt.html
http://www.lightyourreptiles.com/ard3t546in54.html

polyarcturus said:

no, the outer envelope on a bulb(MH) has chemicals that prevent UVB from escaping. you will get similar effect as using from the MH, from 420nm and lower light from the MH but if you want frost... you need UVB to get that you need one of these three current options

MVB
http://www.joshsfrogs.com/exo-terra-solar-glo-160-watt.html?gclid=CIuS0bXYo7ICFcbrKgod3kUALg
CFL
http://www.joshsfrogs.com/lighting/uvb-producing-bulbs/spiral-compact-florescent/exo-terra-repti-glo-compact-26-watt-10-0.html
T5or t8ort12
http://www.joshsfrogs.com/exo-terra-repti-glo-10-0-desert-terrarium-lamp-48-inches-40-watt.html
http://www.lightyourreptiles.com/ard3t546in54.html

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i've thought about using reptile lights but never get around to it. i'm very lazy and not very good at setting things up.

i kind of know what to do with a hammer but things get hazy after that.


i'll have to read up on the coating on MH bulbs.


well, per wiki
"The lamps consist of a small fused quartz or ceramic arc tube which contains the gases and the arc, enclosed inside a larger glass bulb which has a coating to filter out the ultraviolet light produced"

so much for that idea.

BuffaloBanjo said:

http://bigbudsmag.com/grow/how/article/get-more-thc-your-medical-marijuana-plants-using-uv-light-august-2012

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thanks. it's a good article.

here watch this this is a great vid
[video=youtube;aQPC6oAMK4k]http://www.youtube.com/watch?v=aQPC6oAMK4k&feature=player_detailpage[/video]

fatboyOGOF said:

i guess i wasn't as clear as i could have been.

i wanted to know if people kept the glass in or not.

i'm not trying to figure out if i should take mine out. i just took it out.

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Lmfaooooooo

bellybell said:

Lmfaooooooo

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Sep 6, 2012

i'm missing the joke. from 11 years ago. fill me in.

fatboyOGOF said:

Sep 6, 2012

i'm missing the joke. from 11 years ago. fill me in.

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I'm new to this dude. And you said something to the fact of I'm not asking to take glass off i took the glass off. I was stoned thought it was funny probably too funny

fatboyOGOF said:

i've thought about using reptile lights but never get around to it. i'm very lazy and not very good at setting things up.

i kind of know what to do with a hammer but things get hazy after that.


i'll have to read up on the coating on MH bulbs.


well, per wiki
"The lamps consist of a small fused quartz or ceramic arc tube which contains the gases and the arc, enclosed inside a larger glass bulb which has a coating to filter out the ultraviolet light produced"

so much for that idea.

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I knew a guy that would break the outer envelope on his MH bulbs just to get extra UV and that seemed to work until one of the inner ones exploded and damn near burned down his house. One of the main reasons to have that outer shell is to contain red hot fragments should teh tube inside explode tho I've never had one do that since my first 1000W magnetic MH I got new in '82 at Western Water Farms in downtown Vancouver.

I have an enclosed hood but haven't used it often as I don't like the confined footprint. When I have used it I left the glass out. I even rigged it so I can have two bulbs in it. One at each end as I don't need to cool it in my already cool grow room.



Solacure sells UV lights for plants and other applications for the Canadian and US markets and I've long contemplated buying a 4 pack of their T-12 4ft tubes as I have 2 - 1 tube T-12 fixtures I could mount on either side to get good UV coverage.

Last year I bought a 600W 10K finishing bulb to use near the end of flowering but haven't really put it to the test yet to see if it's any improvement. I'm a bit of a sucker for shiny baubles that rarely work as advertised.