mastertek2000
Well-Known Member
My LED light came with UVB and instruction say use them the last 3 weeks of flowering they are 15 WATTS each and it runs 2 for 12/12
Any UVB'ers out there?
- Thread starter Blazer420
- Start date
OttawaGreen
Well-Known Member
Here is where I first read about it and he says two weeks of 12/12 is enough
UVB UVA Study Test Results Increases Medical Marijuana Potency 3-5%: Myth or Magic- The Next UVA UVB Cannabis Marijuana Test Complete
I started earlier than that originally with two cfls as I had to move then around every couple days to try and cover everything. Now that I have tubes on a light mover I will try using just last few weeks too next grow
UVB UVA Study Test Results Increases Medical Marijuana Potency 3-5%: Myth or Magic- The Next UVA UVB Cannabis Marijuana Test Complete
I started earlier than that originally with two cfls as I had to move then around every couple days to try and cover everything. Now that I have tubes on a light mover I will try using just last few weeks too next grow
David Bowman
New Member
I use mine during the last half of flowering and there is definitely an increase in the frostiness of the ladies from the increased trichome production to protect themselves from the increase in UV radiation. The only damage I've seen is when the leaves get too close to the CFLs but that happens anyway regardless of the type of CFL.
somebody else
420 Member
I am going to try some UVB lights. Nothing ventured nothing gained. These seem to have the best bang for the buck ... for a trial anyway.
Exo Terra Reptile UVB200
he big question is how much is enough and how much is too much. After searching hundreds of web pages and hours of reading. I have come to realize that there is no standard default answer. It has to do with genetics. Some strains that have been developed without UVB light may not tolerate it at all. Most if not all greenhouse coverings will filter out UVB. That would explain the mixed reviews of its effectiveness.
In a non cannabis study, seeds were collected from 132 native and introduced plant species growing over a 3,000 m elevational gradient in Hawaii (23deg.N latitude). Seeds were brought back to the University of Maryland, U.S.A. and germinated in the greenhouse under artificial UV lamps simulating 20 and 40% ozone depletions over Honolulu, Hawaii during clear sky conditions on the summer solstice (14.6 and 22.2 kJ m[-2] effective UV-BBE according to an empirical model of Green et al. 1950). In the UV-B radiation treatment simulating a 40% ozone depletion, only 8% of the species collected from sea level to 500 m were tolerant to UV, while tolerance increased markedly in species collected from higher elevations (Table 3). All species collected above 2,000 m were found to be tolerant of UV-B radiation levels simulating a 40% ozone depletion, implying that these plants have adapted to the high levels of UV presently incident at these sites. A greater understanding of the range and types of natural UV protective mechanisms available to plants would provide a better basis upon which to make predictions of the effects of increased levels of solar UV on natural plant communities.
I will try a 13 watt at one end and a 25 watt at the other and no uvb in the middle. 16 to 20 inches from buds. last 2 weeks of flower. Haven't decided how many hours a day yet.
Exo Terra Reptile UVB200
he big question is how much is enough and how much is too much. After searching hundreds of web pages and hours of reading. I have come to realize that there is no standard default answer. It has to do with genetics. Some strains that have been developed without UVB light may not tolerate it at all. Most if not all greenhouse coverings will filter out UVB. That would explain the mixed reviews of its effectiveness.
In a non cannabis study, seeds were collected from 132 native and introduced plant species growing over a 3,000 m elevational gradient in Hawaii (23deg.N latitude). Seeds were brought back to the University of Maryland, U.S.A. and germinated in the greenhouse under artificial UV lamps simulating 20 and 40% ozone depletions over Honolulu, Hawaii during clear sky conditions on the summer solstice (14.6 and 22.2 kJ m[-2] effective UV-BBE according to an empirical model of Green et al. 1950). In the UV-B radiation treatment simulating a 40% ozone depletion, only 8% of the species collected from sea level to 500 m were tolerant to UV, while tolerance increased markedly in species collected from higher elevations (Table 3). All species collected above 2,000 m were found to be tolerant of UV-B radiation levels simulating a 40% ozone depletion, implying that these plants have adapted to the high levels of UV presently incident at these sites. A greater understanding of the range and types of natural UV protective mechanisms available to plants would provide a better basis upon which to make predictions of the effects of increased levels of solar UV on natural plant communities.
I will try a 13 watt at one end and a 25 watt at the other and no uvb in the middle. 16 to 20 inches from buds. last 2 weeks of flower. Haven't decided how many hours a day yet.
OttawaGreen
Well-Known Member
I started with two of those brand 200uvb 25w and they work but not very far so you need to move them around a lot. I had mobile clip on metal hoods to move mine around manually. Now I use tubes on the mover to scan the weed.
Those 200s work well but I suggest getting all big ones don't pay almost same price for less wattage.
Oh wait, you are suggesting you were going to do an experiment? If that was the idea, then go ahead that's a great idea.
The only thing with the CFL's though is that you will only get maybe a 18 inch diameter circle of effect.
Those 200s work well but I suggest getting all big ones don't pay almost same price for less wattage.
Oh wait, you are suggesting you were going to do an experiment? If that was the idea, then go ahead that's a great idea.
The only thing with the CFL's though is that you will only get maybe a 18 inch diameter circle of effect.
somebody else
420 Member
I am going to attach one of these nano fixtures
on each end of this mars hydro light
It's only a 2x4 foot area so it should be an easy test.
on each end of this mars hydro light
It's only a 2x4 foot area so it should be an easy test.
OttawaGreen
Well-Known Member
Nice that will work!
LEDBud
Well-Known Member
I am thinking the 2ft tubes would work best for my LED panels , my panels are 18" long , I will be mounting one 24" tube on either side of the panels, then later buying more to go on the ends , for complete coverage.
at 26w each they also fit in nicely with the LED's low power draw , a perfect match really.
at 26w each they also fit in nicely with the LED's low power draw , a perfect match really.
somebody else
420 Member
Is that a solarstorm? Do you have more specs on the uvb bulbs? A pic of the label on the bulb or something. Any help would be appreciated.My LED light came with UVB and instruction say use them the last 3 weeks of flowering they are 15 WATTS each and it runs 2 for 12/12
mastertek2000
Well-Known Member
here you go i run 2 of these and love them
Hell yea, Im wit it! 
Got these for last few weeks of flower. Only about 54 watts.
Got these for last few weeks of flower. Only about 54 watts.
mastertek2000
Well-Known Member
just remember to much will burn them
From what i read they don't burn?
LEDBud
Well-Known Member
I guess you could technically add to much UVB but it would take some deliberate effort.
UVB is hard on your eyes , sunglasses are a must when working around them , its much harder on your eyes then other light spectrum's.
Lizards and reptiles love it , they tell you not to put it within inches of your reptiles as they will likely look into it which causes eye damage.
The UVB bulbs are not any stronger then the suns UVB light, which will damage your eyes but not your plants.
I would be more concerned with the heat of the bulbs if they were to close ,as with any bulb , then using many of the little 26w CFL's UVB bulbs spread around.
I have read up on the topic and found no mention of UVB overload , perhaps others with first hand experiences can give their findings on UVB burn.
UVB is hard on your eyes , sunglasses are a must when working around them , its much harder on your eyes then other light spectrum's.
Lizards and reptiles love it , they tell you not to put it within inches of your reptiles as they will likely look into it which causes eye damage.
The UVB bulbs are not any stronger then the suns UVB light, which will damage your eyes but not your plants.
I would be more concerned with the heat of the bulbs if they were to close ,as with any bulb , then using many of the little 26w CFL's UVB bulbs spread around.
I have read up on the topic and found no mention of UVB overload , perhaps others with first hand experiences can give their findings on UVB burn.
33 days into flower and have been using UVB lights for about 15 days. Have noticed lots more resin on leaf, but this last two weeks should show on the bud? Have been moving the lights around, not a lot but side to side.
