ProdigalSun
Well-Known Member
Great, more shit to buy. I'm deffy spending more than I'm making, starting to think this whole weed thing is a gimmick to sell some more lights fans nutes and filters.
UVA/UVB the real deal. A must read topic for all growers.
- Thread starter GreenVet
- Start date
twistedwords
Well-Known Member
So if this is what you are after and will only add a little percentage of gain, then just get yourself a Ceramic Metal Halide bulb and be done. This bulb will give you everything you could possibly need.
ProdigalSun
Well-Known Member
I think this should be a sticky.
Sunbiz1
Well-Known Member
Unfortunately, I do not have comparison pics to share b/c I'm not a very good photographer...and I own a Canon EOS(lol). What I would show if I could are the quantities of trichomes produced on identical clones run both with and without UV/B supplementation indoors.
The $70 I spent adding 320 extra watts of MV was well worth it as trich quantities were increased a good 30% or more with supplementation.
I am sold.
The $70 I spent adding 320 extra watts of MV was well worth it as trich quantities were increased a good 30% or more with supplementation.
I am sold.
Sunbiz1
Well-Known Member
As usual, the price tag on these is a major stumbling block on my end:
"Red LED Array Light Source (Power Supply Not Included) $220.00"
How many are needed for 25 SF or a 5X5 area?.
cannawizard
Well-Known Member
~honestly.. that is still something of a mystery on my end, nothing solid in-regards to coverage/intensity
i'm pretty sure someone on this site has a good formula (watt per sq / LED) 
I wouldn't waste your money on UV LEDs at this point even the most powerful ones are still way under powered to give you any kind of coverage or penetration. Looking at those LEDs the top power rated ones are in the UVa range and only 400mW max watts. The UVb true ones in the 310-320nm range are only 180mW max. You're much better off going Mercury Vapor or T5s for a lot less money. I've been happy with these T5s so far http://www.lightyourreptiles.com/ard3t546in54.html Not sure what MV lights people are using but those seem to be more of spot coverage so you'd need more for your area and they produce more heat. The Mega-Ray zoo lamps look to be decent for MV though but the dude wants you to have a VM meter before he'll sell you them. Don't seem em on his site anymore either.
~Dankster~420
Well-Known Member
I have to say it really does help. I have 1 reptile UV bulb running along side of my 800 watt LED system and can see a difference between flowering room #2 & flowering room #1 where plain HPS/MH run.Put in two 10. Desert Reptile UVB 26w bulbs in 33 days into flowering on my 1st grow. 1st grow yeah, but Ive seen my fair share of fire and Im pretty certain those lights were the cause of it.
Scope some
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Sunbiz1
Well-Known Member
My plants agree, they are content with MV...I use multiple 160W spots.
medicinehuman
Well-Known Member
I've been using a 26 watt 10.0 UVB light for some grows that I have going now and in a couple of weeks I'll know if it helped. I have grown this plant for a couple of years so it should be noticeable if it has more kick. I'll throw my 2 cents in then.
GroErr
Well-Known Member
Good thread, was thinking of trying this in my next round, sounds like there may be something to it. Looking for LED's (with heavy UVA/UVB) though, and thinking of running them for 4-6 hours in the middle of the cycle. I'm running LED side-lights in veg right now, running them 6 hours in the middle of an 18/6 cycle and the side shoots are exploding in comparison to my last veg run under the same light and space/environment.
ProdigalSun
Well-Known Member
The Tutankhuman I grew ripened 11 days earlier than her mother.
rene112388
Well-Known Member
the potency at higher altitudes outdoors has been attributed to the cold as well. also most say while the gain more crystals they lose yield in this scenario
of course its not good for the health of the plant, its a form of stressing, just like shocking with cold, but whats interesting about this is the claim that cirtian levels of uvb are high enough for the potency effect but low enough not to affect yield, i wonder if the same line of thinking could be applied to cold shocking? ive read any form of stressing can lead to hermie problems though
this is one of the main opinions in this thread and its garbage, of course it would be awsome to scientifically quantify the effects, but your still taking it from a random internet source. we all understand that PROOF isn't there, but to dismiss the idea because of lack of proof is... well thats fine if that your style, don't use uvb. but don't dog others based on that alone.
so your saying everything about growing cannabis is known. I disagree, we are in the golden age of weed now, maybe uvb works, maybe it aint worth the watts, if you want to disagree that's your right, but to say if it were any good we'd be implementing it already isn't a very valid reason. i also think we all understand its not essential for good herb, so the statement so many have made that thier garden does fine without it doesn;t hold water either because thats not to say it would.nt be a little better with it
my opinion is im guessing uvb isn't as effecive as a florescent or hps of the same watts in the same place, but who knows. its definatly on my list of things to vary (but i got to finish the list of things to control before i can get to that list). Its been a minute since a thread has kept me interested for 14 pages, thanx much
Pepe le skunk
Well-Known Member
Rene, cold will stress the plants and could cause them to die. Photosynthesis stops and a plant will die below 26 degrees if exposed for multiple days. Potency is not directly related to cold temperatures as the plant ripens and builds thc. Light spectrum/ intensity and uvb have been shown to effect potency more than anything except genetics.. Yield is effected by pruning and the amount of nutrients available to it. Uvb has very minimul effect on yield. Pruning to main branches in flower has the biggest effect on yield and you can take that to the bank.
The plant buds (resin ie: trichcome heads) react to the presence of uvb and the thc resin acts as a sunscreen increasing it's quality and quantity to protect itself. As far as levels go, the better the bulb, the better the results. (10% and 12% are a good starting point.) Coverage using these bulbs as supplemental lighting on the sides have produced the results most effectly within 1 ft of the bulbs. So you want to be able to provide all sides equal as possible exposure to the lights. Indoors because of the inverse square law the target area is 18 inches of height X 12 inches in depth for maximum exposure. So hang the lights horizontal along the side within that 18 inch bud zone and rotate the plants every few days for coverage. Again it is supplemental only and you will need more intense main lighting. (HID)
Remember HPS has zero UVB usable light. MH has some but if there is glass between, it filters it out. Most important time is week 3 on in flower. The main lights provide the intensity and correct spectrum for growth, not thc development or enhanced thc development. The genetics of the drug type strain are responsible for it's presence in the first place. UVB forces the plant to produce it in abundance.
As for hermies, what you need to know is flowering some sativa strains to early can cause hermies way before uvb will. So will some peoples poor excuse of selective breeding (ie pollen chucker's) without testing plants using stress to eliminate bad selections. (Swerve) lol.
Light leaks and not knowing to give them 12 hrs uninterupted darkness after a lighting foul takes place in flower can also cause male flowers to form on some light sensitive strains (weak selecting). One last thing to know is some hermies have been found to be the most potent examples in certain strains. Thai's, even GG4 came from a hermie as did the diesels and chemdog in their accidental breeding.
As for proof, it is out there. From the ones who have done it. Others just might not want you to believe it, so yours won't be as good as theres. Happens all the time in this industry.
For many years I thought I knew what to do. The truth is not until someone showed me a few things did I realize I didn't have a clue.
And that's no shit.
Yodaweed
Well-Known Member
I have been running UV-B light for about 1 year now and it works best when used in either intervals of 15 minutes off and on during the day or for 2 hours or less in the last 2 hours of light. Anymore can burst the heads of your trics, any less and I feel like it doesn't do anything. My UV-B bulb is built on to my LED
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Lysergicpt
Well-Known Member
do you guys keep the lights on right until harvest day ? or you turn them off a few days earlier ?
I'm asking cause this is my first grow with UVB and i already did my fair share of research but i do not seem to find any "valid" on if to keep them until harvest or not ?
I'm asking cause this is my first grow with UVB and i already did my fair share of research but i do not seem to find any "valid" on if to keep them until harvest or not ?