Using uv light to increase resin production

polyarcturus

Well-Known Member
Those bulbs suck! They put out so much heat they are useless for our hobby! The fluorescent bulbs don't put out heat and they last longer. The fluorescents will work great for SOG but your right they dont have much canopy penetration.

The bulbs you posted would work really good if you built a homemade aircooled relfector and ran them so they wouldn't interfere with your HPS lighting.
you are wrong, they do put out heat but not unmangable heat, just need a small fan blowing across.

also they will last much longer and emit UVB much longer than fluorescent, and if cooled well a years worth of use is not unreasonable. the issue is the 2 different kinds of glass used, the chemicals in florescents, and the amount of UVC emitted causing polarization in the glass.

they have much better spread and intensity(penetration), while fluorescent is limited in both distance and penetration, it has more spread when used up close, has the advantage of being placed vertically, which effectively means more UVB across more of the plant, but in a horizontal situation as most are forced to use by the design of their grow room, the MVB would be more efficient, UVB spectrum wise, price and wattage wise.

the order of the most effcient come in this order, specialty MH bulbs,mega ray, they use special glass emits less heat, a little less uvb than MVB but with the added bonus of more blue spectrum, MVB(mercury vapor bulb, specialty reptile ones), then last but not least in the case of micro growers fluorescent.
 

PJ Diaz

Well-Known Member
you are wrong, they do put out heat but not unmangable heat, just need a small fan blowing across.

also they will last much longer and emit UVB much longer than fluorescent, and if cooled well a years worth of use is not unreasonable. the issue is the 2 different kinds of glass used, the chemicals in florescents, and the amount of UVC emitted causing polarization in the glass.

they have much better spread and intensity(penetration), while fluorescent is limited in both distance and penetration, it has more spread when used up close, has the advantage of being placed vertically, which effectively means more UVB across more of the plant, but in a horizontal situation as most are forced to use by the design of their grow room, the MVB would be more efficient, UVB spectrum wise, price and wattage wise.

the order of the most effcient come in this order, specialty MH bulbs,mega ray, they use special glass emits less heat, a little less uvb than MVB but with the added bonus of more blue spectrum, MVB(mercury vapor bulb, specialty reptile ones), then last but not least in the case of micro growers fluorescent.
What he said ^^

..except this part..

the order of the most effcient come in this order, specialty MH bulbs,mega ray, they use special glass emits less heat, a little less uvb than MVB but with the added bonus of more blue spectrum, MVB(mercury vapor bulb, specialty reptile ones), then last but not least in the case of micro growers fluorescent.
I believe there are some HID type external ballasted MV lamps which are the most efficient form of UV. I could be wrong though, but I'd bet $20.
 

PJ Diaz

Well-Known Member
Those bulbs suck! They put out so much heat they are useless for our hobby!
So, are HPS and MH also useless due to the heat? No, they are not. We as indoor growers simply need to manage the heat.

Seriously, the flouro uvb lamps are a complete waste of money, unless you are growing a couple of tiny plants, or have a shitload of the lights all over the place.
 

Nightmarecreature

Active Member
Not true! Flouros should work great! You know you only need 200milliwatts/cm2 of UVB! I will stick to flouros! Reptile MH more heat and electricity, it's overkill.

You need so little UVB you could get away with LED UVB!
 

PJ Diaz

Well-Known Member
Not true! Flouros should work great! You know you only need 200milliwatts/cm2 of UVB! I will stick to flouros! Reptile MH more heat and electricity, it's overkill.

You need so little UVB you could get away with LED UVB!
200milliwatts/cm2 of UVB? IDK where you came up with that number, but let's look at the math of what that would mean real quick..

Lets assume a 4 x 4 growing space. 48 inches is about 122 cm. 122 x 122 = 14884, so the space is 14,884 cm2.

200milliwatts = .2watts

14,884 cm2 x .2watts = 2976.8 watts

Surely you can't expect to have 3kw of those little reptile tubes in your tent do you?
 

Nightmarecreature

Active Member
200milliwatts/cm2 of UVB? IDK where you came up with that number, but let's look at the math of what that would mean real quick..

Lets assume a 4 x 4 growing space. 48 inches is about 122 cm. 122 x 122 = 14884, so the space is 14,884 cm2.

200milliwatts = .2watts

14,884 cm2 x .2watts = 2976.8 watts

Surely you can't expect to have 3kw of those little reptile tubes in your tent do you?
I was talking about the bulb output, not room coverage. There was a great youtube video showing good success with these flouros, it has been removed.He was using Repti Glo 5.0 200mW/cm2 UVB. The one you posted is the one I ment to post and will work perfect. I also meant microwatt, not milliwatt. 200 microwatts = 0.0002 watts

"Ultraviolet radiation is expressed in microwatt per square centimetre (mW/cm2) and varies
tremendously from the poles (low) towards the equator (high). The amount of UVB radiation
received on the equator on a clear day at noon lies around 270 mW/cm2. However, this high
amount of radiation decreases as the day passes, in the same way that it had increased since
sunrise and taking into consideration that not all days are clear."

"Many commercial reptile lights today exceed this 270 mW/cm2 in an attempt to show the greatest
UVB radiation. Some even exceed over 2000 mW/cm2, which is absolutely dangerous! Especially
if you know that the 270 value of the sun is only measured at high noon on a clear day while most
light bulbs are on between 10 and 12 hours with constant values."



Repti Glo 5.0 200mW/cm2 UVB
Repti Glo 10.0 400mW/cm2 UVB


 

polyarcturus

Well-Known Member
What he said ^^

..except this part..



I believe there are some HID type external ballasted MV lamps which are the most efficient form of UV. I could be wrong though, but I'd bet $20.

there are external ballasted MV bulbs, though they produce more UV, they produce less usable PAR, i guess it would matter on your opinion more UV or more PAR.
 

hereshegrows

Well-Known Member
If you really want information overload on UV lighting in general, I found so much on the subject by reading posts from Tanning salon owners. They deal with similar issues and know their lights.
 

PJ Diaz

Well-Known Member
200milliwatts/cm2 of UVB? IDK where you came up with that number, but let's look at the math of what that would mean real quick..

Lets assume a 4 x 4 growing space. 48 inches is about 122 cm. 122 x 122 = 14884, so the space is 14,884 cm2.

200milliwatts = .2watts

14,884 cm2 x .2watts = 2976.8 watts

Surely you can't expect to have 3kw of those little reptile tubes in your tent do you?
I was talking about the bulb output, not room coverage. There was a great youtube video showing good success with these flouros, it has been removed.He was using Repti Glo 5.0 200mW/cm2 UVB. The one you posted is the one I ment to post and will work perfect. I also meant microwatt, not milliwatt. 200 microwatts = 0.0002 watts

"Ultraviolet radiation is expressed in microwatt per square centimetre (mW/cm2) and varies
tremendously from the poles (low) towards the equator (high). The amount of UVB radiation
received on the equator on a clear day at noon lies around 270 mW/cm2. However, this high
amount of radiation decreases as the day passes, in the same way that it had increased since
sunrise and taking into consideration that not all days are clear."

"Many commercial reptile lights today exceed this 270 mW/cm2 in an attempt to show the greatest
UVB radiation. Some even exceed over 2000 mW/cm2, which is absolutely dangerous! Especially
if you know that the 270 value of the sun is only measured at high noon on a clear day while most
light bulbs are on between 10 and 12 hours with constant values."



Repti Glo 5.0 200mW/cm2 UVB
Repti Glo 10.0 400mW/cm2 UVB


Have you actually used flouro UV lamps in a full grow? I have used them with a clone strain that I've also run without the t5 UV tubes. IMO, the UV tubes are worthless and don't make any noticeable difference.
 

cannawizard

Well-Known Member
actually.. the amount of UVB around (near) the equator is <est> 400+ µW/cm² :) and its rising.. the readings were taken on clear days around noon.

#cheers
 

polyarcturus

Well-Known Member

whazzup

Well-Known Member
Many MH lamps are NOT rated for open fixtures! Take good care of selecting the correct lamp. When placed behind (normal) glass filters, you will lose the UV they might emit. Stay away from any UV LED that are not made of glass.
 

polyarcturus

Well-Known Member
Many MH lamps are NOT rated for open fixtures! Take good care of selecting the correct lamp. When placed behind (normal) glass filters, you will lose the UV they might emit. Stay away from any UV LED that are not made of glass.
these are made with cheap glass envelopes, not only do they emit UVB they emit tons of UVA and enough UVC to be very dangerous.
and applies to both MH and MVB
 

whazzup

Well-Known Member
You can never really see from the glass if it is blocking UV or not, sometimes it is specifically mentioned. But very important is that MH or CMH rated for open fixture have a double glass envelope, or a cylinder of glass around the arc tube, or a wire circling around the arctube, or even several of these measurements together to prevent the outer bulb from shattering when the arc tube should violently explode. MH go down with a real big bang sometimes.
 

polyarcturus

Well-Known Member
the ansi code would note whether it was for an open rated fixture or not. the law requires a posting of this information it is always specifically mentioned.

sometimes they do add a wire around arc tube or a double envelope(inner one usually filled with argon) but this has nothing to do with the UV or the fixture rating, that is still relevant to the type of glass used and its chemical properties. they just do this as safety precaution but its not required or has to be noted in the ANSI code
 
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