What's new
  • Happy Birthday ICMag! Been 20 years since Gypsy Nirvana created the forum! We are celebrating with a 4/20 Giveaway and by launching a new Patreon tier called "420club". You can read more here.
  • Important notice: ICMag's T.O.U. has been updated. Please review it here. For your convenience, it is also available in the main forum menu, under 'Quick Links"!

UVB VS NO UVB Side by Side

J

John LOQUE

Member
i've just received a reptisun 26 W cfl, i will try it very soon, today i think.

Those cfl don't provide a complete spectrum i think, only uv's and that's what i want .

BUT

I was wondering, about hid's uvb high power bulbs, since they provide a complete spectrum, including heat, nobody has ever tried a complete flowering cycle under ONLY those big hid uvb bulbs ?

I think i will try it in a little tent, 2x160 watts uvb's bulbs and nothing more, just for curiousity ...
 
N

neverforget4/20

Member
Only Ornamental said:
Personally, I don't readily trust compact UV fluos... but the last few years brought considerable progress. I prefer the HID based ones such as the Mega-Ray brand which has an exceptionally high quality and very long life span; a compact and most HID have to be changed after about one year due to a loss in UV. Well, in the case of plants, they may hold longer as reptiles/animals use a different spectrum of UV. UVB is important for vitamin D synthesis and the part of the UV spectrum 'bleaching' first whereas plants use (according to the current lack of knowledge) mostly UVA, where compacts aren't that much behind of HIDs as they used to be just 5 years back.
Check the UV light survey or other similar independent sites.

PS I don't trust in manufacturers descriptions because they used to be (and likely still are) VERY WRONG, highly deceptive, and in certain cases such as Repti-Glo outright lies.
Click to expand...

Hey OO,

We have chatted before on TLG.

Can you describe how you set up the exo terra. Have you observed andor measured improvements in flavor or potency?
 
Only Ornamental

Only Ornamental

Spiritually inspired agnostic mad scientist
Veteran
Just re-read my post you quoted... sorry about the bad English, it sounds awful!

Exo Terra?
That's THE ONE brand you SHOULD NEVER use (NO MATTER which light bulb)! Unless the blue CFL night light I can't find anymore... This one might eventually be used experimentally as source of far-red light (though it's complete and utter stupidity to use it in a terrarium); according to the manufacturer's specification (which, in case of Exo Terra, are usually completely wrong and deceptive), the cut-off is perfect (regarding plant phytochromes) and situated exactly between red and far red.
CFLs from most other brands are okay nowadays. Just check their UV output every 6 months with a UV meter ;) . Many HID bulbs, especially the cheap ones or those of less reputable brands, have an uneven UV distribution which is slightly offset to the visible light focus. Others are used punctual (spot lights aka basking lights) and not as true flood lights; that's the advantage of CFLs over HIDs.
 
Bongstar420

Bongstar420

Member
LOL..."organic" soils.

Not necessary. LOL

Hasn't anyone figured out what is in the stuff that actually results in the difference?

I can tell you one thing, I can purchase pure compounds and get results like the "best organics" out there for far less effort.

I can also synthesize my own poor mans brew which does almost the same thing.

If UVB increases THC, its either due to increased resin gland output at the expense of growth rate/dry weight or some minor increase in isomerization reactions which can be accomplished simply by increasing the lux and breeding more THCA synthase into the line.

I only noticed a more desirable terpene profile from UVB and it was fairly minor in difference. Using the right juice accomplishes far far more. Its definitely not worth less growth and extra equipment.

I have been doing GC/MS for over a year now. I got an 18%THC off a cut with high UVB/ 400-470nm and 27% THC off the same cut with almost no UVB at all under mostly standard HPS.

Sam_Skunkman said:
What happened to Green science? Please run the test and analyze the results and post them!!
I ran a test a bit like this 20 years ago.
I had several different clones of high THC varieties, and industrial hemp, and a wild cannabis variety from the mountains.
I placed each clone in rows of five so they had a chance to be exposed to too high of levels, medium, and low levels, depending on the distance from the light sources.
To cut to the chase, no increase compared to controls without UV-B.
In fact the plants closest to the lights were a bit zapped and had lower plant weights and lower Cannabinoid levels.
(In my own opinion using organic soils to increase root mass, which gives Cannabis with improved terpene yield and better Cannabis yield is much better then UV-B supplement.)

Tonygreen,
As for On page 31 if you scroll down you get into some good stuff and an interesting hypothesis about thc. They quote Lydon and Pate, but Pate did my experiments with me
setting them up and measuring the UV-B levels, as well as testing the results on our GC.
He was unable to increase the THC levels. Lydon thinks CBD can be converted to THC, but most Cannabis grown in the west has no CBD to start with. Lydon also only dosed the plants with UV-B for only 40 days, part of those when the plant was still in veg. He also said no increase in THC in hemp plants so I guess CBD does not get converted to THC by UVB?
We tried several times, zero THC increase. I have never seen any lab results that showed an increase in THC from UVB exposure, I have never seen Lydon's work replicated, except when I tried but got no increase in THC.
As for "Marijuana Optics" anyone that reads it and thinks it is science needs to stop smoking so much.
Get all three of Lydon's papers and try to repeat the work, if I remember correctly he did not even use clones for the work, for sure in the case of Lydon's 1985 Thesis, I think the 1987 paper also. I will go find the papers and re-read them....

-SamS
Click to expand...
 
N

neverforget4/20

Member
"If UVB increases THC, its either due to increased resin gland output at the expense of growth rate/dry weight or some minor increase in isomerization reactions which can be accomplished simply by increasing the lux and breeding more THCA synthase into the line.

I only noticed a more desirable terpene profile from UVB and it was fairly minor in difference. Using the right juice accomplishes far far more. Its definitely not worth less growth and extra equipment.

I have been doing GC/MS for over a year now. I got an 18%THC off a cut with high UVB/ 400-470nm and 27% THC off the same cut with almost no UVB at all under mostly standard HPS."

Do you have any citations for the claim "If UVB increases THC, its either due to increased resin gland output at the expense of growth rate/dry weight or some minor increase in isomerization reactions"

When you say "does the same thing" how are you making that determination?
Also the thc% reflects a single metric. It's not much of an overall indicator of flavor, potency or desirability.


"I got an 18%THC off a cut with high UVB/ 400-470nm" No that is not UVB.
 
Last edited:
D

DrBlaze

New member
neverforget4/20 said:
"I got an 18%THC off a cut with high UVB/ 400-470nm" No that is not UVB.
Click to expand...

That's not even UVA


attachment.php

View image in gallery​
 

Attachments

  • LightSpectrum.jpg
    LightSpectrum.jpg
    15.8 KB · Views: 42
N

neverforget4/20

Member
Pay close attention to the spacing bro. In my set-up the agromax toasts broad indica leaves that are within~18" or so. I used the hortilux uv bulb until the last 3 weeks then switched to the agromax. Plants coming down soon. I will post a followup.
 
G

Guest

So has anyone contacted the OP about why he never followed up with more info? I don't think I have enough posts to do it.
 
B

burmese

Active member
best what i seen on internet i think its lucky reptile bright sun series if its true what they claim for,,
from my growing memories i saw some higher chance of flower delaying with uvb cfls and higher chance of plants will to reflower//repotted, closer light source// but i grow 1212micros//
 
N

neverforget4/20

Member
Megaprop said:
The UV treated buds certainly looked frostier. Any updates on the way?
Click to expand...

I slacked on updating. Apologies. It does seem that uvb exposure results in a bit more frost. Im not sure it results in more or better potency though.

Also genetics that have high frost potential are frosty AF without the uvb. Purely anecdotal: my buds that have been well dosed with uvb seem to give a stonier, spacier, somewhat hypnotic stone.
Latest plants grown without uvb:


 
Phaeton

Phaeton

Speed of Dark
Veteran
I began documenting a garden very similar to what the thread owner has done. Starting with a test room and side by sides with UVB levels from 2000 uw (2 mw) down to 20 uw (.02 mw). Then a garden with levels from 70 uw through 200 uw.

Between some strains not responding at all to veg levels affecting later growth and clones with and without also making a difference I gave it up after six months.

While I felt I was reporting on personal results of the garden unique in my home, I got butthurt by those accusing me of an agenda.

The subject is fascinating and complex, I do use varying levels of UVB in all stages of all plants. Stems with the hull still covering the cotyledons are getting UVB.

But trying to give what is basically a physics course combined with molecular biology in the limited confines of a garden thread is daunting. Hundreds of hours of study and years of fieldwork, the relevant information is covered in available college level courses.

Anecdotal results from single plantings can give as many conflicting conclusions as plants used in the testing.
 
led05

led05

Chasing The Present
Phaeton said:
I began documenting a garden very similar to what the thread owner has done. Starting with a test room and side by sides with UVB levels from 2000 uw (2 mw) down to 20 uw (.02 mw). Then a garden with levels from 70 uw through 200 uw.

Between some strains not responding at all to veg levels affecting later growth and clones with and without also making a difference I gave it up after six months.

While I felt I was reporting on personal results of the garden unique in my home, I got butthurt by those accusing me of an agenda.

The subject is fascinating and complex, I do use varying levels of UVB in all stages of all plants. Stems with the hull still covering the cotyledons are getting UVB.

But trying to give what is basically a physics course combined with molecular biology in the limited confines of a garden thread is daunting. Hundreds of hours of study and years of fieldwork, the relevant information is covered in available college level courses.

Anecdotal results from single plantings can give as many conflicting conclusions as plants used in the testing.
Click to expand...

Phaeton

I've done quite a bit of research (all anecdotal unfortunately, no lab) but did find what I consider by far the best UVB bulbs accessible to most and that will throw substantial UVB mid range 3-4' plus, easily, this could be of benefit for you or others at a minimum.

Look into the Ushio Mid Range UVB bulbs (306nm) - there are various sizes, I found them as I know about dermatological lamps which is one of their uses. They put out 10+ UV Index over 3' away using 15 watts or so, think the 15w ones are the size I use, there are various ones as mentioned.

I tested everything there out there, MH, CMH, Aquarium MH, LED, HPS, all types, the Ushio mid-range UVB are best bang for buck, BY FAR...

I tested with this meter, hits the right peaks for UVB, near perfectly, also nice to see in a measurement I understand, UV Index

https://www.solarmeter.com/model65.html


I found that UVB def does things, especially on the terpene side... Grow some regular herbs (basil, oregano etc.) in a Greenhouse vs outside, the outside stuff has a lot more flavor etc to it due to a number of factors but UVB being present outside vs not under Poly is one of them, for sure, same holds true inside for most herbs, the plant of interest here, especially , run with REAL UVB and you'll see.

Cheers, fwiw, I know Sam doesn't agree with me on this, oh well
[FONT=Arial, Helvetica, sans-serif]
[/FONT]
 
G

Guest

led05 said:
Phaeton

I've done quite a bit of research (all anecdotal unfortunately, no lab) but did find what I consider by far the best UVB bulbs accessible to most and that will throw substantial UVB mid range 3-4' plus, easily, this could be of benefit for you or others at a minimum.

Look into the Ushio Mid Range UVB bulbs (306nm) - there are various sizes, I found them as I know about dermatological lamps which is one of their uses. They put out 10+ UV Index over 3' away using 15 watts or so, think the 15w ones are the size I use, there are various ones as mentioned.

I tested everything there out there, MH, CMH, Aquarium MH, LED, HPS, all types, the Ushio mid-range UVB are best bang for buck, BY FAR...

I tested with this meter, hits the right peaks for UVB, near perfectly, also nice to see in a measurement I understand, UV Index

https://www.solarmeter.com/model65.html


I found that UVB def does things, especially on the terpene side... Grow some regular herbs (basil, oregano etc.) in a Greenhouse vs outside, the outside stuff has a lot more flavor etc to it due to a number of factors but UVB being present outside vs not under Poly is one of them, for sure, same holds true inside for most herbs, the plant of interest here, especially , run with REAL UVB and you'll see.

Cheers, fwiw, I know Sam doesn't agree with me on this, oh well
[FONT=Arial, Helvetica, sans-serif]
[/FONT]
Click to expand...


I have been following UVB info and have used Reptisun T5 in a small grow. I don't have room for a side by side so I am not making any claims but it makes sense that it adds in my mind. After all the info I could glean it seemed that the best UVB bulbs only reached 5-10 inches or so and watching you tube vids testing seemed to bear that out. Yet you say 3 FEET??! Wow. If that's verifiable that's impressive.
 
You must log in or register to reply here.

Latest posts

Latest posts

Top