10.0 Uvb Light

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peach

Well-Known Member
born2killspam said:
Stray x-rays can be formed without much difficulty.. TV's have x-ray protection features because they aren't that uncommon in HV applications.. You can build a diy x-ray projector with old vacuum tubes.. Best I've seen was able to make out a nail in a 2x4.. Its actually quite dangerous..:)
Its also been discovered that peeling scotch tape in a vacuum produces non-negligable amounts of x-rays.. Its a pretty recent find though, so I don't think its clear how useful that may end up being..
Don't get me wrong, x-rays are another thing not worth caring about here since voltages aren't in the dozens of kV range, and I agree with pretty much everything you just said..
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You're right about the TV's, although they don't produce much. low current + <20kV = not a lot and soft

The scotch tape is new to me, funny shit though!
 
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peach

Well-Known Member
Hobbes, not sure about the light you mentioned, you want sub 320nm.

Does anyone know why UVA isn't possibly helping this effect? Why are we specifically after just UVB?

If UV really works, I could always look at how much some customized & fit to the task bulbs might be.

For intensity, nothing is going to beat the HID low pressure mercury bulbs. Stealthy mentioned using a double ended bulb, that could be similar.

A standard reptile fluoro will give around 3w for the whole bulb (30w in), a medical UVB will be around 11w UVB for 100W of input. The Osram Ultra-Vitalux is about 3W out for 300W in. The MegaRay will be similar I'd guess.

To get sunlight intensity over a large area at anything other than right up close or way too focused is going to need a high UVB out wattage.

It would then be a matter of finding a HID that can pour it out and that's cheaper to buy than the fluoros. I'll investigate (edit: done). Osram do a lot of HID bulbs (supratec) with UVB outputs in tens of watts. Wish more of it was going into UVB instead of UVA.

http://www.osram.com/_global/pdf/Professional/General_Lighting/UV_IR/105S003GB_DB_Supratec_UV.pdf

Here are the rough prices for Osram's Supratec line;

HSC 400-221 460 W (90W UVA 22w UVB) = ~40 Euros

HTC 400-221 460 W R7s (95W UVA 25W UVB) = ~25 Euros (looking good, the other higher wattage HTC bulbs may be good as well, they're cheaper than the HSC because they have an electrode on either end of the bulb which isn't an issue for us, may be better to have a couple of the lower wattages spread out)

HSC 500-221 570 W GY9,5 (110W UVA 28W UVB) = ~60 Euros

HSC 1000-221 1000 W (210W UVA 40W UVB) = ~80 Euros

These are used for curing plastics and adhesives and come with a special warning that they're only to be used in enclosed spaces - they're industrial lamps.

I've been doing a lot of searching, but only Osram have published some UVB wattage figures for HID so far. The others seem to focus on UVA (tanning) and UVC (disinfection). Some help finding other HID manufacturers that give their bulbs UVB figures would be useful.
 
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peach

Well-Known Member
born2killspam said:
I know M57 (175W MH) ballasts are compatible with mercury bulbs.. Dunno about other sizes, but its likely..
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I've found a couple of specific mercury vapor ballasts, not sure if you can use standard MH ballasts atm. Be good if you can, I don't want to be paying out top dollar for some specialized deal when a used 400w MH would do.
 
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born2killspam

Well-Known Member
Thats what I was thinking too.. I have a Sylvania M57/H39 magnetic ballast.. M57 pertains to 175W MH, H39 to 175W MV..
Funny thing though, I just read a Sylvania document that said 'Some manufacturers no longer make MV ballasts, but label MH ballasts to operate both lamps.'
It also outlined that MV bulbs run on MH ballasts will have higher lumens/W, and reduced lamp life..
Kinda funny that Sylvania wrote that, and labels their ballasts like that..
Anyways, M57/H39 (175W), M59/H33 (400W), and M47/H36 (1000W) labeled ballasts can run MV bulbs..
 
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peach

Well-Known Member
I've read a few contrasting opinions as well. I'm consulting a more reliable source and will get back when I hear.

I need to do some math on these bulbs to work out what kind of area they're going to cover with sunlight intensity. I have a feeling it may help if they have a reflector in front of them as well to spread it out more evenly - they're very small and extremely high power.

I'd be bothered that if we start messing with these lamps and posting it up here, someone might run one without realizing how much UVB is actually coming off it. They'll need to be in a tent / room and off whenever the door is opened.

Still be interested to know how everyone came to decide it was just UVB we want? That's a genuine question, I just haven't heard why it's UVB only and not UVA as well.
 
HOHO

HOHO

New Member
i don't think its doing any thing to my trichs both sides of my garden look the same..:-( i don't now if its the type of bulb i have but i would have to agree at this point that the flouro tubes are prolly the better of the bulbs...it'll be the smoke test that it comes down to though. :joint::hump:
 
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peach

Well-Known Member
What a bitch HOHO!

With so many variables in the bulbs at the moment it's going to be hard getting it down until we have the UV levels and distribution sorted. Hopefully you'll notice a difference in the two when it's important. :)

Sorry if you've already said, which bulb are you running, how much per day, how old is it and how far is it from the canopy? Could you upload a picture of your plants & canopy so I can see exactly how it's set up? I'd really like to try and figure out what values are hitting your trichs
 
HOHO

HOHO

New Member
i assume your talking to me?...i'm the one who bought the zoo med 160 watt flood light and its brand new...well burned in for about 100 or so hours.
i'm really not good at the picture part but here's a couple i took today for u..
the bulb is about 8 inches from the canopy and on all day..
 

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peach

Well-Known Member
HOHO said:
i assume your talking to me?...i'm the one who bought the zoo med 160 watt flood light and its brand new...well burned in for about 100 or so hours.
i'm really not good at the picture part but here's a couple i took today for u..
the bulb is about 8 inches from the canopy and on all day..
Click to expand...

Sorry HOHO, I did mean you.

I'm guessing you're talking about the ZooMed PowerSun 160W. Here's a picture of it's output against your canopy (I've had to take a rough guess at scaling the graph with the idea that it's about 8" from the canopy). Getting an even 250 uW/cm^2 could be a big part of this UVB experiment. Crank it down about 5" if you have anymore grow time left buddy and see if you get any difference. The MegaRay by ZooMed has a much tighter focused cone under it's bulb.


 
moodster

moodster

Well-Known Member
ive been running my 26w cfl reptile light for 6 hours a day and i noticed when i harvested my plant there were a few seeds in the bud even though they were clones from a female plant could the uvb light have caused this as b4 when i grew this strain without uvb and didnt have any seeds help ive turned it off for 4 now was it too close also the top bud closest to the light grew all deformed and didnt bud right
 
HOHO

HOHO

New Member
hey thats pretty slick peach!..i will drop it tomorrow and see what happens,i first had it about 4 or 5 inches and i was preventing the pistols from coming out the tops of the buds but now that i think about it, that was when it was fresh out of the box now that its burned in i'm sure it wont hurt...i will keep u posted and i took a bud from each side of the room today and put on my ballast so to sample the difference at 5th week, will prolly be able to smoke tomorrow or sunday..
 
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peach

Well-Known Member
Hobbes said:
Is a Uw/cm^2 the same as a microwatt/cm^2 ?


.

bongsmilie
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Yep, it should actually be the letter Mu from the greek alphabet;

http://en.wikipedia.org/wiki/Greek_alphabet

Which signifies micro / millionth in measurements.



HOHO said:
hey thats pretty slick peach!..i will drop it tomorrow and see what happens,i first had it about 4 or 5 inches and i was preventing the pistols from coming out the tops of the buds but now that i think about it, that was when it was fresh out of the box now that its burned in i'm sure it wont hurt...i will keep u posted and i took a bud from each side of the room today and put on my ballast so to sample the difference at 5th week, will prolly be able to smoke tomorrow or sunday..
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No problem, I'm just grateful to the guy that's done all the measuring of those bulbs. I think that one was burnt in for 100 hours +.

According to the PDF someone posted earlier on UV bulbs, the MegaRay actually has a lower output when it's first turned on. It raises after around 100h and then gradually falls again over the months.

These lamps seem extremely touchy to bulb shape and placement looking at the graphs of output. I mean, this really looks like a thing where what's good for one strain will be shit for another (with different bud distribution).

Which makes it hard to predict a lighting requirement until you see the budding pattern you'll be lighting.
 
topfuel29

topfuel29

Well-Known Member
Heres my results:

(1) 20 watt UVB 10.0 light on for 12 hours per day in the flowering cycle.

(1) Garden Green Plant
(1) Skunk

The Garden Green plant went nuts with trichomes.
This plant might have been a hash strain.
Buds close to the UVB light produced more trichomes.
Probly 2x as buds away from the UVB light.

The skunk plant was the true test of the UVB light
Trichome production on the cola, (the side that was facing the UVB light)
was about 4x more dense with trichomes that the Cola side that was away from the UVB Light.
 
moodster

moodster

Well-Known Member
topfuel29 said:
Heres my results:

(1) 20 watt UVB 10.0 light on for 12 hours per day in the flowering cycle.

(1) Garden Green Plant
(1) Skunk

The Garden Green plant went nuts with trichomes.
This plant might have been a hash strain.
Buds close to the UVB light produced more trichomes.
Probly 2x as buds away from the UVB light.

The skunk plant was the true test of the UVB light
Trichome production on the cola, (the side that was facing the UVB light)
was about 4x more dense with trichomes that the Cola side that was away from the UVB Light.
Click to expand...
did they hermie out on you m8 mine did
 
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