Moe.Red
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When use mine, anything closer than 2 ft. Causes burning.Having done this before and essentially burning the leaves up in the process, I'm trying to understand why my results are different.
How many uW/cm2 should I be expecting for "a pretty good burst?"
Am I being over cautious in listening to the plants?
Having done this before and essentially burning the leaves up in the process, I'm trying to understand why my results are different.
How many uW/cm2 should I be expecting for "a pretty good burst?"
Am I being over cautious in listening to the plants?
When use mine, anything closer than 2 ft. Causes burning.
Do you have one table that combines your offerings and which size grow/height is appropriate. I had no idea about your up close offerings and obviously my interest is high and i knew about you and some of your products. Going with one of the universal offerings based on what I have learned today from you.One other thing: Distance matters. Remember that inverse square law I spoke of? If you put a bulb designed for 24" distance at 6" distance, that isn't 4x the power, that is 16x the power (inversely proportional to the square of the distance). That will fry them. That's why you need the right power level for the distance you are using. We have four different UVB lamps available because of this, plus a 2' bulb.
I'm not sure what lamp you are using, so I can't be certain why yours is burning. Odds are, it is the wrong power for that distance, however.
Well saidSo, I wasn't going to get involved in the thread, as I'd rather spend my time in the room then doing mental work but let's look at the first 4 discrepancies I found between Dennis Brown's comments and Dr. B from Utah State. I'm not saying which is correct cause I don't know, just pointing out the comments which are opposite of each other. There may (and probably will be more) as the thread progresses.
1. Brown says use the entire grow vs. Dr. B says use just last 2-3 weeks for overall plant health.
2. Brown says Indica's handle the UV-B better vs. Dr. B says sativa's handle it much better. Indica's absorb more UV-B because of their larger leaf surface, sativa's skinny leaves are exposed less.
3. Brown says UV-B has little to no impact (3% max) on yield as Dr. B says it can have a larger negative impact over time.
4. Brown says bulbs are the best way for UV-B and Dr. B says UV-B diodes are available (and surely coming) but are very expensive to use so right now it's limited. But prices will fall and then will become more mainstream in fixtures.
Much of what both guys are saying are similar in many ways, but not all. For those who are interested, you can find all of Dr. B.'s videos on Youtube, and I (or others) have posted many of the links in my 3 Gavita threads. I'll again reiterate that Mr. Brown is the owner of a company that sells these bulbs and has motivation to lead you in a certain direction. Dr. B is a professor, who teaches and researches light and it's effects on plants (he has the only U.S. license to use marijuana in his testing facility) for these purposes.
I'm not taking sides either way, I just want to get to the truth. We all want to grow stronger pot, that's the end game. And I hope Dennis doesn't take all this in a negative way, we all appreciate his input and hope to continue the discussion in a meaningful way.
I agree with number two. Our understanding of what indica is, and what sativa is, is incorrect. It isn't as simple as leaf width. My understanding is, plants grown closer to equator, and high elevation has higher resistance to uvb. This can include what we understand as indica and sativa.There are numerous contradictions from some comments made above and those in Dr. Bruce Bugbee's (Utah St.) video's on uv-b......... I'm not saying which are correct or not, but I found 4 already in a quick read. Take everything with a grain of salt, and do not rely on this one or that one as being correct.
I will say Dr. B has no skin in the game, and has been researching lighting and marijuana specifically for many years, and tends to be the "standard" when it comes to these things. I'm trying to keep an open mind, but it's important to understand everyone's motivation and ulterior motives when posting specific products and claims.
I will say I think each person's personal experience while using UV-B would probably be the best source of relevant info on the subject. Moe is off to a good start, and I'll be introducing UV-B to my room in just a few weeks. So let's not jump to an conclusions just yet, the ship has just left the harbor.
I agree with number two. Our understanding of what indica is, and what sativa is, is incorrect. It isn't as simple as leaf width. My understanding is, plants grown closer to equator, and high elevation has higher resistance to uvb. This can include what we understand as indica and sativa.
I'm not taking sides either way, I just want to get to the truth. We all want to grow stronger pot, that's the end game. And I hope Dennis doesn't take all this in a negative way, we all appreciate his input and hope to continue the discussion in a meaningful way.
A good example of how this experience helps is that you don't see us talking about UVB % when comparing products because we know the number is rather useless. It is complicated to explain in a short post, but it is. I can easily make a 10% lamp that will burn you faster than a 20%, for example. This gets into the physics, which most people aren't interested in. They just want results.
True (hell I run his gear) and also the vast majority of his work was on hemp. When he gets going in the videos, he uses Hemp and drug cannabis pretty much interchangeably, something that always concerned me.While i think bruce is a decent guy, he's also selling his apogee meters by shilling the work of his grad students to a niche with extraordinary interest that has been starved of access to scientific knowledge in the field by a seriously imperfect world that targeted this plant for bad reasons. The ROI on those videos has to be great for him!
Let's call a spade a spade. He's not some pure-hearted, just for the science saint. And i have been very enthusiastic about several of his videos!
That is correct, but you also have to consider that during the summer, plants grown farther from the equator have longer days, so the net UVB is higher. It is an oversimplification to just say "indicas can handle more" but it is an oversimplification that most people can understand and that works as a "rule of thumb".
As for previous comments as to discrepancies between my claims and the claims of the doc from Utah, my observations are based on a ton of anecdotal information and field tests from thousands of growers over a 20 year period. I would imagine it is a much larger data set. His data is probably more stringently gathered but significantly smaller. It isn't always that one is right and one is wrong, it can often be that there are other circumstances coming into play that one or both of us haven't taken into account. Universities have only recently been able to do any testing without fear of losing federal money, btw. We never had to worry about that, although most of our testing has been doing outside of the law.
Because each strain can be so different in how it reacts to anything (light, uv, nutes, water, etc.) it is very hard to make sweeping generalizations that are 100% correct. We are forced to make generalizations simply because that is what people want, and that information is fairly useful. Also, while he seems to be focused mainly on THC and UVB, our research is a bit broader.
True (hell I run his gear) and also the vast majority of his work was on hemp. When he gets going in the videos, he uses Hemp and drug cannabis pretty much interchangeably, something that always concerned me.
I view my job as listening to everyone and reading everything I can on subjects like this that interest me. Separating the wheat from the chaff is both difficult and rewarding as you see it play out before your eyes.I agree with this but he does say he has consultants in the medical field of cannabis.
He also has many years of plant lighting research well before cannabis or hemp was allowed.
dr. Bugby is sure not focused only on uvb and thc. He is the guy who designed all the new apogee meters to read wider spectrum after discovering the par meters are too narrow for full photosynthetic spectrums. And he is a career agriculture professor. Nutrients and lighting are his specialties.
If you have not seen his work (and your comment says you have not) you should. Your research is to sell products. He has no similar agenda. And he now runs the cannabis lab in the university of Utah. They have many plant chambers conducting experiments. He has a tour video that shows it all.
you said it yourself. You have tons of anecdotal information. I would hope you are interested in peer reviewed studies and properly conducted testing on the subject.
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