UVB for full 12 hours during flowering

[hempknightt]

I know theres like 2 threads about UVB light already but I couldnt find them... So im just gonna start a new one. Any reason why people recommend not having them on for the whole 12 hours during flowering? Its much easier for me to keep them on with my other lights rather then having them on there own timer that might get fucked up and stay on during my night hours, but I dont want to do it if its gonna be bad for my babiessss. Thoughts? Please share.

 

[Detroit J420]

be careful with uvb, i use 2 60 watt zoo mega rays and ive turned some indicas into a hardcore amber herion high. uv rays cause aging, you got uva uv and uvb im no scientist, but the sativas are more tolerent to turning amber, difinatly use them though just dont over do it

 

[hempknightt]

I turn them off when I go into my grow room but thats like 30 mins a day off maybe, so like 11 and a half hours on. Is turning amber supposed to be a bad thing? Isnt it just a normal part of the plants growth? Im growing mostly sativas too

 

[Detroit J420]

mostly sativas, your good then just watch your trichromes, too much amber isnt good but you shouldnt have that prob.. it doesnt take much uv to piss the bitch off she's gonna be wett and sticky..

 

[hempknightt]

sounds good to me!

 

[Bonzo Mendoza]

Most uvb lights (even the best quality 10% uv ones) emit such low uv energy that it probably is not going to hurt anything unless you have the light closer than 8 inches.

I agree that it is unwise to use more than one hour of uvb in the last two weeks of flowering.

 

[BenRound]

As far as I am concerned turning it off for part of the cycle is silly. Its something like "My plant cant handle 5000 watts of HPS light for the full 12 hours, so I only have them on for part of the cycle" Ahhh OK... so then dont use 5000 watts on one plant, use an appropriate amount for the full cycle.

My LED puts out some UVB (yeah the full 12, baby), but I plan to bump it up some on future grows.

 

[Rcb]

As far as I am concerned turning it off for part of the cycle is silly. Its something like "My plant cant handle 5000 watts of HPS light for the full 12 hours, so I only have them on for part of the cycle" Ahhh OK... so then dont use 5000 watts on one plant, use an appropriate amount for the full cycle.

My LED puts out some UVB (yeah the full 12, baby), but I plan to bump it up some on future grows.

What light do you have?

 

[BenRound]

What light do you have?

I have a HTG 135w 7 band. Other LEDs also have UVB, such as the Black Star w/ 6 bands.

Im sure its not much UVB. I have plans on adding some 10% UVB CFLs or perhaps 10% T8s--- that is if I dont get a CMH, which I may because I will soon have a 400w HPS ballast to run it on.

 

[Rcb]

do you know what percent of uvb a cmh has? Also where would one find those t8 bulbs at?
also concerning the time on/off for uvb ii would use them all the time the other lights are on.

 

[Bonzo Mendoza]

Running uvb light when there is alot of resin on the flower tops will degrade the thc. Cannabis resin absorbs uvb light (that is why the Great Grower put it there) to protect the plant tissues.

Cannabinoid resin is marijuana sunblock.

There is no reason to keep alot of uvb on the plant prior to harvest.

The dude that intends to run uvb for a full 12 hours is just going to cook down large amounts of fresh THC that is exposed to high uv into CBD.

 

[JustCoasting]

I know theres like 2 threads about UVB light already but I couldnt find them... So im just gonna start a new one. Any reason why people recommend not having them on for the whole 12 hours during flowering? Its much easier for me to keep them on with my other lights rather then having them on there own timer that might get fucked up and stay on during my night hours, but I dont want to do it if its gonna be bad for my babiessss. Thoughts? Please share.

I so love your avatar, if I could rep you, I would...

 

[alphawolf.hack]

uv shines from all hid bulbs and the sun all day long

 

[hempknightt]

Yeah i basically figured there is UV all day when growing outside. I guess i just though it might be more concentrated in a bulb or something? Lol

 

[FranJan]

Sorry Ben but Blackstars and HTG have UVA (390 nm) not UVB. If your panel has glass in front of the diodes I doubt it has UVB, since UVB doesn't pass through most glass, plus UVB diodes are xpensive and Blackstars ain't (I own 2 240w). But please if I'm wrong educate me.

 

[Phaeton]

This is a CMH reading.

View attachment 2041457 This is a Reptisun 10 reading.

View attachment 2041461 This is an ArcadiaD3+ reading.

I love the CMH's, they are all I use on top of my veg plants, but they do not provide UVB.

The Arcadia's are T5's and wil cause sunburn.

200 uw and 300 uw are the min and max at the leaf, arcadias have to be held back 18" while the reptisuns are unable to get close enough.

In nature UV is nondirectional and does not come directly from the sun, plants utilize it much more effectively from the side.

 

[alphawolf.hack]

as usual ther is some cocky know it all newb who has been growing for a year and read couple books. well i used to kinda be like that. but then again i have read thousands of books (not just marijuana growing)

start with google LIGHT SPECTRUM EMITED FROM HID this should give you some handy charts that tell you what percentage of energy is converted in to the different spectrum and heat.mh is about 40% hps is about 5% most is blocked by reflector glass and bulb glass so hps is about nil. mh still will put off about 20% thru the glass.

next your going to want to know the difference between coated bulbs and un-coated. and horticultural and industrial. there are varying differences, but un-coated horticultural and industrial bulbs both give off uv.

please do your research kids. research does not have to directly apply to growing some of the most useful info i have found out about ventilation was from an hvac book

actually you know what don't give me any rep.

 

[Kite High]

as usual ther is some cocky know it all newb who has been growing for a year and read couple books. well i used to kinda be like that. but then again i have read thousands of books (not just marijuana growing)

start with google LIGHT SPECTRUM EMITED FROM HID this should give you some handy charts that tell you what percentage of energy is converted in to the different spectrum and heat.mh is about 40% hps is about 5% most is blocked by reflector glass and bulb glass so hps is about nil. mh still will put off about 20% thru the glass.

next your going to want to know the difference between coated bulbs and un-coated. and horticultural and industrial. there are varying differences, but un-coated horticultural and industrial bulbs both give off uv.

please do your research kids. research does not have to directly apply to growing some of the most useful info i have found out about ventilation was from an hvac book

actually you know what don't give me any rep.

well the UVB meter I have shows NO uvb...sorry I read alot as well but will trust my METER more than anything anyone here has to say...go read some more then you will find u r in error...or better yet, get meters and know what you saw and did rather than what you READ

 

[Phaeton]

Damn, I guess it takes all kinds. Ignorant is how we all are born, stupid is deliberate.

Coated, uncoated, industrial, horticultural, even the blacklight disco HID's do not put out UVB in any quantity a plant can detect.
Nothing to argue about, that is what is nice about science. It is, or it isn't.

Note the picture of the UVB meter pointed at the CMH. 1 uw (microwatt). A cloudy day is over 50. A reptisun 10 at 20" puts out 50.
1 is the minimum the meter can read. 200 starts affecting plants. Under 25 has no effect, on people or plants.

I like answering questions and helping folks, but aggresive stupid is irritating.

A full time test budroom for a year helped, but even before that I did not post crap or berate people out of ignorance.

 

[alphawolf.hack]

where do i buy this meter whats is its accuracy, what is its method of measurement?(IR, RF, Laser, ect) tell me these thing and i will buy a uv meter have actually never heard of one maybe your right i am going buy what i have read and what has supposedly been tested by scientists. i guess i could be wrong or your meter off (unlikely even i know this) but there has been research that proves uv is emited from hid bulbs. are we considering all uv or just uvb so does the meter measure only uvb? can we see some results from other hid bulbs? im srry not be aggro but i have read so much on this and for me to be wrong would suck but happens. but then again i hear so much bullshit passed around its not funny i mean look at my avatar nobodys is even reading anymore