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Does reflector glass block U V?

Rembetis

Active member
Hi everyone,

sorry if this has been asked before but I have searched several times and nothing comes up. Wondering if reflector glass bocks UV? I use the Hortilux bulbs and it doesnt make sense to spend the extra cash if I am not getting the full benefit. I am considering removing the glass but not sure if that will cause a heat problem in my 4x4 tent. Also considering moving up to a 1000 watt. Too much for my tent?

I like the tropical Sativas and I am happy with my results but am looking to step up my game so that is one reason I was considering the move to the 1000 watt bulbs
 

Cvh

Well-known member
Supermod
I thought that the glass indeed shielded the most of the UV.
I know that here are a few guys who run or has run 'unshielded'.

Hopefully they can come in and give some enlightenment.
 

Hold Your Fire

Finding my way back home
Veteran
I use 4x4 tents and I remove the glass from my reflector with a 600w bulb but not a 1000w.
I may try it this winter but not confident doing so now.
 

wutwut

Well-known member
Veteran
I use 4x4 tents and I remove the glass from my reflector with a 600w bulb but not a 1000w.
I may try it this winter but not confident doing so now.

what kind of fans do you have? how many intake hole do you keep open? i also have 4x4'7 tent 600w hps but temps go so high i have to dim 400w.. 6" ducting diameter
 

CannaRed

Cannabinerd
The light has to travel from inside the bulb through a layer of glass, sometimes 2 layers like some CMH, and then the glass of the hood or reflector. I would think with every pass thru glass we would be losing some UV.

I always wondered about the clear plastic that is wrapped on greenhouses.
I worked at a few nurseries, and a few of the greenhouses were actually 2 layers of plastic with air inflating in-between to provide insulation.
 

troutman

Seed Whore
Just so you all know there's no such thing as perfectly clear glass. They all block a small amount of
light. But it's best to not look directly at bulbs regardless if the reflector has a glass shield or not.
 

Hold Your Fire

Finding my way back home
Veteran
what kind of fans do you have? how many intake hole do you keep open? i also have 4x4'7 tent 600w hps but temps go so high i have to dim 400w.. 6" ducting diameter

My tents are in a basement. Temps only hit 70F in the middle of the day on the hottest days, and not very often. My lights are off during the day.

I only leave one 6 inch round vent on the bottom open.

I do run air cooled hoods with the glass removed.

A reflector that isn't air cooled wouldn't work.

Fans are 6 inch vortex vented outside with a 6 inch vivosun oscillating fan clipped to one of the poles inside.
 

Rembetis

Active member
Hortilux makes the bulb glass to allow the UV to pass thru. When I read that on their site it got me thinking about whether or not the reflector glass was blocking UV so I asked them.

I spend the money to use their bulbs so I want to get all the benefits. My plan is to run the hood open once it gets cold enough. Its still too hot so I had to put the glass back on for now. Still vegging so doesnt matter for now anyway. I was really wanting to see what the UV does for flowering with a Tropical Sativa
 

romanoweed

Well-known member
you can type into google-pictures: the name of a given Light, add the word spectrum, and you often find spectrogramm.
Everything from 100nm to 380nm is uv. Also sunlight has not as much uv as other frequencies.. but some, and thats what you are looking for.

Shure its interesting to try get enough uv trough taking away the glass. But be carefull, the glass might been added cause the danger of uv. There are Sunglasses made for Indoorlights to protect your Eyes
 

Rembetis

Active member
I always wear sunglasses. I have glaucoma and cataracts so I am not about to chance any damage from lights.

I already know the spectrum of the bulb. I dont need to google it, its on Hortilux's page. Thats why I chose their bulbs.

I'm not sure what you are talking about with the glass being added for safety. It is an air cooled hood so it has to have the glass but in the winter I can remove the glass and use it as a non air cooled hood since the bulbs are rated for open fixture
 

growshopfrank

Well-known member
Veteran
The light has to travel from inside the bulb through a layer of glass, sometimes 2 layers like some CMH, and then the glass of the hood or reflector. I would think with every pass thru glass we would be losing some UV.

I always wondered about the clear plastic that is wrapped on greenhouses.
I worked at a few nurseries, and a few of the greenhouses were actually 2 layers of plastic with air inflating in-between to provide insulation.

Been a minute but here
https://gpnmag.com/article/uv-transmitting-greenhouse-glazing/
 
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