UVB for full 12 hours during flowering

I've been doing UVB research every day for a couple of months and from what I understand, the sun puts out about 220 here in texas and I wanted to beat that, but it's practically impossible to find the mW of any UVB lamp that isn't made for snakes and lizards. I'm thinking a tanning light would be a good bet because the reptiles will get hurt if there's a lot of UVB and the reptile lights also put out significant amounts of UVA. I just want UVB; UVA is no good for cannabis. I just bought a light that puts out 1700 microwatts of UVB @ 5" that's made for plant growth, but it took an entire day of calling shitloads of people trying to figure out the wattage and I have no idea what the output would be @ the more reasonable distance of about 18"-36". I'm going to run it for 5hrs per day and I will post some results. Although, I will have no idea if this is an improvement because it is my first grow.

I also hate know-it-all dickheads, so why don't you stop being one. I'm completely new to this, but even I know HIDs (EVEN metal halides) don't put out SIGNIFICANT UVB. I can't believe you are dumb enough to suggest his meter is wrong and you're right. You read something from a "scientist." Well, fuck me. It must be true. I can't stand people with bad attitudes that insult other people's intelligence when they can't even capitalize letters and use punctuation.

ArcadiaD3+ T5 HO 12% uvb from http://www.lightyourreptiles.com/
The reading is 122 uw at 29", enough to make a large difference as it is on the full 12 hours, not just noon.


Three (3) Reptisun 10 from Zoo Med
The reading is 130 at 16", this works for lower buds but does not reach the cola. Arcadia is the choice for overkill.

A high noon reading is not necesarry if the UVB is on all day. 150uw at the leaf is running close to the bottom of the noticable effects range. Anything over 50 helps but you have to know what to look for. A noob can feel the difference at 150, a big difference and the stunting is minimal.

I almost did not come back because of dumb dick, but why let him wreck good information exchange.

If you're emitting PURELY uvb what would happen if you were to run it 24/7? Would it affect the photoperiodism because the wavelength is so close to the blue range?

hey man did alot of reading i was in the wrong. you were right although most horticultural bulbs claim to output uv-a. i was reading about reptiles and they stated that uv rays ar present in hid bulbs but the outer envolope is coated in a chemical to prevent its escape. so i am stupid. im on the same train tho about to order some reptisun 10 25w for both sides of my flowering room. my qusetion is would it be better to do 12 hours or 6 with the uv bulbs? my mh that i did believe but now know isnt putting off uv-b runs for 6 hours alrady to emulate noon. (another question would on 40w 4 foot bulb be better? the room size is 4x2x4)

also the only reaon i believed that hids where putting off uv is logic. because why would a sell horticultural bulb that doesnt provide all of the spectrum it can provide? but i am a stupid cocky asshole who needed told off because i was trying to be too smart when i didnt have the proper info. also srry for questioning your meter although is ran of off whats known as a photodiode or possibly a photocathode

Some saying about taking a bigger man to admit when he was wrong, fits here. +rep to both, well handled

Perma Baked said:

If you're emitting PURELY uvb what would happen if you were to run it 24/7? Would it affect the photoperiodism because the wavelength is so close to the blue range?

Click to expand...

I'd say most definitely, but I have yet to find a light that ONLY emits UVB rays. They all spit out at least a bit of UV-A and usually some visible light.

I really have got to get one of those meters. I'm so jealous

The plants need to eat, pure UVB does not have food value, you can't live on just coffee.
I did try a violet/yellow HID, actually I thought I was on to something and have 9 of them. Their spectrum was 404-440 nm and 590 nm, everything else in the 1-2% range.
So much violet it looked red to me.
I lost the whole crop. Stupid is as stupid does, I'm not exempt either. That was when I built the test room and started killing them one at a time, cheaper that way.

Then I bought meters.
Then I changed lights.
Then I built a new room with more new lights.

Be sure before you go down this road, be really sure, my new car turned into a growroom. Now I'm on foot.

Killer setup brotha, you got a journal or anything setup for your room? If you dont you should take pictures, I am looking to setup my room for UVB next harvest, so I would like to get a nice little head start. Of course I could do the trial and error and waste some money, but ehhhhh

I used an Arcadia D3 12% UVB light for the full 12hrs of my photoperiod on my last grow, plant seemed to love it

BlackJack fertilizer has a great primer on lighting and uv light,uv provides cell strength,to put it simply,and what could be wrong with that.

^Above is my modified old skool TV Cab.. its running a dimmible 250W Lumatek ballast that kicks back from 250w to 175w to 150w.. I am running a 250W MH 6500K for Veg and a SunMaster Dual spec 250W in Flower.



^ I bought the above UV-B lamp for that much wanted THC/Resin increase..just wanted to check if this lamp will be fine to use in my setup..and want to hear other peoples opinions if there a better lamp I could use in this Cab?

Many Thanks - ZTELTHY

*that bulb is good for your SCROG/StealthCab setup i'd suggest running the uvb with the same time schedule as your HID, imo i don't think you need anything stronger than that 10.0 bulb for a one plant SCROG..

#cheers