Trichomes, THC and UVB light.....

DannyGreenEyes

Well-Known Member
I'm about to start my first grow, have three 400w on the way (2hps & 1mh) and I'm just learning bout UV exposure. I'm starting with 8 plants, 2 Sour Diesel, 2 Citrus Diesel, 2 Blueberry, 1 Grape Ape, & 1 Oak Leaf.

I've read that UVA exposure is important as UVB rays use them somehow, but overexposure to UVA can be dangerous. I also heard that the reptile lights give off much more UVA than UVB.

That said, I'll probably start off with 2 reptile lamps due to cash flow problems. I'll start with one on each side of the 2 rows of plants. I'll hang them hi at first and I'll slowly move them closer to the plant till I'm as close as I can be, and I'm going to try using them during veg to see if it helps.

I'm going to be looking to upgrade as soon as I can. Very early in this thread someone mentioned that www.reptileuv.com was developing a UV Metal Halide, well it's here and they're selling them. I just wish I could read the charts. Can someone read them and let us all know how they stack up against the other types, and also let us know if it's overkill or if they just took regular MHs and renamed them.

Can you also break down the UVA & UVC levels in these UV MHs.

Thanks.
 

DaveCoulier

Well-Known Member
Thats a good bulb if your plants are directly underneath it. It just doesn't have the width of light I would want. I plan on using the Mega-Ray 160w Narrow Flood lamp.

You can see how it performs here:

http://www.uvguide.co.uk/spreadchartcombo.htm

Almost 48 inch wingspan versus the 24 or so for the MH you posted.

That MH is also $120. At least it doesn't produce extra heat like the flood lamps though.
 

DannyGreenEyes

Well-Known Member
Thats a good bulb if your plants are directly underneath it. It just doesn't have the width of light I would want. I plan on using the Mega-Ray 160w Narrow Flood lamp.

You can see how it performs here:

http://www.uvguide.co.uk/spreadchartcombo.htm

Almost 48 inch wingspan versus the 24 or so for the MH you posted.

That MH is also $120. At least it doesn't produce extra heat like the flood lamps though.

Thanks for the info, what a bummer though. I didn't see the pic with the spotlights and I was assuming that all metal halide bulbs were made in the same shape as a MH Grow light and use the same kind of ballast. I can't imagine why they wouldn't make them that way but I hope they start making them soon. Spotlights are going to be harder to work with, even the wide angle ones. Oh well, we can't have everything I guess.

Can anyone tell me how to figure out the UVA, UVB, & UVC output of a bulb. I guess I'm going to start with aquarium lamps and I want to buy the one with the lowest UVA output. Problem is these bulbs don't list a breakdown of the UV spectrums and in most cases don't even list the total UV output.
 

MAXXDANK

Member
hey there folks ..... nice to see the thread alive and well again. I guess I have a couple of thoughts that come from this last round above. I had a substantial folder of background material that disappeared with my last hard drive. I have slowly been pulling together all those that I can find. I have not gone back through this thread but I would have sworn that I made reference to stuff along the way. And it is also my recollection that the discussion was as said above, not about whether or not there was increased trichome and thc production with higher incidence of uv light, it was a discussion about how and why the biology, the physics, the whatever? I suppose it was one of the underlying thread assumptions that it had been shown with reasonable certainty that the addition of uv light to an indoor grow improved the results - yield improved, but to a lessor extent than quality-potency).

I also believe that there was a component of this discussion that revolved around the shortcomings of indoor growing. It was not only the argument that pot from equatorial regions which measurably receive the greatest uv intensity was greatest among pot strains. With the advancement in lighting and metrics, the thought of "what's missing" what can we do to "mimic" sunlight more closely? this is based on the observed results that people achieve with indoor and outdoor grows. It is a belief held by me that outdoor pot given the same due care and attention indoor growing receives but with the sun's real energy, the monsters you can grow are out of this world. So there really were multiple drivers behind seeking a better understanding of the relationship between uv and thc/trichome.

That is not to say that that assumption to preface our discussion was valid. Those of us who were the initiators of this thread were believers of the assumption, so for us it was valid.

In response to a comment about the thread being "cluttered" .... I guess that just a clear representation of the commotion going on from my neck up .... hahahahaha! and for that reason, the closest I will get to doing a proper experiment (remember, I am only a scientist of 30 years) is what I am doing now. Same seed batch, same strain, same growing conditions (mostly), same love and care, ADDED UVB light. Comparing the same seed same strain at day 44 showed the obvious difference between the two grows ...... they are barely recognized as the same .... but I am the first to acknowledge that there are many many factorz, that influence the result of what you see. For me, the answer is this; I believe that to grow indoors, it is beneficial to make attempts to improve the "quality" of that indoor environment. We all make great efforts in this regard. In my case, I also believe supplemental CO2 up to 1600ppm is beneficial. I realize that these "new" conditions require adjustments in water and food and other parameters. Similarly, I believe adding uv light is "improving" the quality of my environment. and with a sample size of one as my current experience, we'll have to wait and see what the measured results (wet/dry weight) will be. But even with that .... this is still one grow, one event ,and the next one and the next one and the next will each be different. Based on what I have seen so far with this grow, I'll very likely be including the uv lights into my successive grows ........ walking on!!~~
brilliant.....
 

Bonzo Mendoza

New Member
Early Results of uv-b experiment in gorw room: SUCCESS!!!

I have a 2x600w HPS and double 48" 32 watt t8 fixture with two 5.0 Reptisun uv-b flourescent tubes. The garden has a few Bubblicious, some Short Ryder, several AK48, and some Deisel. I have Northern Lights too, but the NL are never exposed to the uv-b. The uv-b fisture was suspended along the edge of the garden - only one side of the garden received uv-b illuminance/ The bulbs were hung 3-4 inches above the plants. According to earlier posts i hve made, I calculated that the uv-b exposure at that range to be around 100 milliwats of uv-b - equivalent to the uv index in an American Sunbelt city on a cloudy summer day.

For all strains, some seeds produced more healthy plants than othersl; for example, the Bubbleicious produced both weak and striong plants, while all of the AK48 plants came up strong.

For the healthy plants, all strains respond well to the uv-b. Weak or damaged plants suffered damage under the uv-b.

The plants are a full two weeks into flowering.

The uv-b lights are causing the Bubbleicious and AK plants to make terpenes like crazy - compared to the other plants, the bud feel damp to the touch and your fingers come away REEKING. The Bubbleicious smells exactly like a piece of Bazooka bubblegum!!!

The Short Ryders are not under the uv-b; now, about 50 days from seed sprout, the Short Ryders have lots of nice resiny piney-smelling buds. The Short Ryder are going to be good smoking (but small yeild), but those uv-b AK's are going to be the stars of the grow this season.

I still have a month and a half for flowering plus another 4 weeks to finish the late sprouted Northern Lights.

I am definitely going to go get another $35 t8 48" fisture at Home Depot and order two new Reptisun 10.0 bulbs.

Actually I need two new t8 fixtures from Home Depot - after less than 30 days, the one I have is already having problems and needs to be replaced (fucking chink rubbish). HD sells a 48" t8 with an EXCELLENT polished nickel reflector (painted metel does not reflect uv-b) - that is really a good reflector for such a low price.

These three strains were a waste of time and money:
Nirvana Super Skunk (poor germination, way too many males, very poor flowering by surviving females)
Nirvana Kaya Gold (a weak indica)
Nirvana free seeds
 

mmjmon22

Member
So, is this thread dead? If so, why? Was there ever any great conclusions? Everyone continuing to use these uv bulbs in their grows?
 
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