Stunned
Well-Known Member
Find it hard to believe that it didn't go well with you and your flowering attempt at 1k umols.....
I'd be looking at something other than light
I'd be looking at something other than light
Please help me understand this umol's/par
GodOfPot
Well-Known Member
Nowhere did I try to imply that a member of our forum has a better understanding than those who wrote the paper, simply that he has a better understanding of it then you.
If this was the conclusion you drew;
then you're not understanding the article at all. You're also not the only one on the forums who's read peer reviewed studies, and there's more than just one. Realize that while it's a good study it isn't by any means perfect either and does have flaws, which was all PGR tried to point out to you.
I've seen PGR's info and sources in various threads, seen him/her help people in different threads and pointing them in the direction of good info which is why I stated (s)/he has good advice, all I've seen from you is misunderstanding and arrogance
- Thread starter
- #23
vyserage
Well-Known Member
Thanks everyone 
I have plenty of information to work with and have a better 'feel' for what im wanting (on my ToDo list is to make my tent minimum 500-700 ppfd in the corners and sides and of course better in the middle). I'll likely buy a measureing tool to test my lights so i can see where i need to add more, etc.
Ideally i would love to have atleast 1000 - 1200 in middle and minimum 500 on corners, 700 preferred. Anything above 1200 and im sure i would need to add co2 which i havent even looked into at all yet. i dont think i can do that since the tent is in my room with me.
I have plenty of information to work with and have a better 'feel' for what im wanting (on my ToDo list is to make my tent minimum 500-700 ppfd in the corners and sides and of course better in the middle). I'll likely buy a measureing tool to test my lights so i can see where i need to add more, etc.Ideally i would love to have atleast 1000 - 1200 in middle and minimum 500 on corners, 700 preferred. Anything above 1200 and im sure i would need to add co2 which i havent even looked into at all yet. i dont think i can do that since the tent is in my room with me.
PurpleGunRack
Well-Known Member
PurpleGunRack
Well-Known Member
CO2 is not that easy to add... Most of us use an extraction fan which means our room/tent basically becomes a wind tunnel.
If the air is exchanged several times every minute, most of the CO2 gimmicks on the market are more or less useless, and certainly not worth the money, space and labour.
In a highly environmentally controlled room that doesn't rely on extraction to keep temperatures down, adding CO2 is a worthwhile upgrade, especially if run on a control unit so it's always in the right range.
To a certain degree the uptake of CO2 gets higher as temperatures rise, so a CO2 enhanched room might give the highest yield, but a room kept relatively cool will give weed with a more complex terpene profile and thus better taste and medical properties.
I'm not sure, but I have an idea that the cannabinoid profile is also somewhat affected by temperature.
Hope to see a lot more studies on this in the coming years
I'm thinking about how one could build a liquid cooled linear light strip lamp covering xx square feet with +1200 PPFD, and make a solid light solution for a CO2 enhanced room
If the air is exchanged several times every minute, most of the CO2 gimmicks on the market are more or less useless, and certainly not worth the money, space and labour.
In a highly environmentally controlled room that doesn't rely on extraction to keep temperatures down, adding CO2 is a worthwhile upgrade, especially if run on a control unit so it's always in the right range.
To a certain degree the uptake of CO2 gets higher as temperatures rise, so a CO2 enhanched room might give the highest yield, but a room kept relatively cool will give weed with a more complex terpene profile and thus better taste and medical properties.
I'm not sure, but I have an idea that the cannabinoid profile is also somewhat affected by temperature.
Hope to see a lot more studies on this in the coming years
I'm thinking about how one could build a liquid cooled linear light strip lamp covering xx square feet with +1200 PPFD, and make a solid light solution for a CO2 enhanced room
Walter melon
New Member
Wow.... Well thanks for pointing me in the right direction folks. I guess I'll stick with YouTube and fourm people's advice from now on and pass on actual funded study's that have proven correct. Mostly because they aren't "perfect". Fourm grows I guess are a bit more perfect. Not taking anything away from PGR at all though. But wow.
Re: Plz help me understand this umol's/par
Lol.
I don't want to disparage that study just because it comes from the same place that grows that sh!tty "government cannabis" for the few people who are still in the federal cannabis program from years back, but I did get a chuckle when I saw that someone had brought it up again.
That study, while interesting and somewhat useful (at least if someone takes a little time to read the 546K .PDF instead of just the abstract), has been critiqued many times by many people on many forums. Here is one example, posted elsewhere but by someone who is a member here:
There is a relationship between temperature, CO₂ levels, and the amount of light-energy that a plant can actually process. Above a certain amount of light (varies), you're not going to see any benefit at ambient CO₂ and average grow room temperatures - and you'll have reached the point of diminishing returns well below that; achieving the maximum production from a given space is all well and good, lol, but once one reaches the point of diminishing returns, it can be more productive to increase the size of the grow space and spread the light out instead of merely continuing to add more light into the same space (although it is true that far more people grow with too little light for their space than too much). That study obviously did not take DLI into consideration, since the people performing it were only giving the plants light for very short periods of time when measuring things, instead of throughout an entire 24-hour period. Mexican sativas require a lot more light than a 100% indica (or the majority of hybrids) - had they used a pure Afghani, for example, they almost certainly would have ended up with lower numbers. Et cetera.
I cannot claim to understand every nuance of that study. But I did learn a lot more after reading it (more than once) than I did from looking at the extract. AND... Those Internet forum discussions that some don't seem to think much of also added to my knowledge, lol, because some pretty intelligent people were nice enough to take the time to explain things in layman's terms. And, since someone used the term "peer review," well... Often (sadly, not always), when incorrect information is posted on a cannabis forum as being factual, sooner or later someone will wander into the thread and call, "Bullsh!t." Because many of the people that frequent cannabis forums... grow cannabis - and a lot of them have been doing so for decades - and not all of us are of the "this worked for me last time, so it MUST be the best way to do it" mindset, and are always looking to learn how to improve, if not for our own production, at least because we like to learn things. I'd sort of consider this to be peer review, LMAO.
EDIT: But if you're only interested in growing a specific (unnamed) Mexican strain of cannabis, are only interested in growing leaves, and don't plan on giving your plants more than 45 minutes of light at a time, lol, then that study might have all the data that you need....
Lol.
I don't want to disparage that study just because it comes from the same place that grows that sh!tty "government cannabis" for the few people who are still in the federal cannabis program from years back, but I did get a chuckle when I saw that someone had brought it up again.
That study, while interesting and somewhat useful (at least if someone takes a little time to read the 546K .PDF instead of just the abstract), has been critiqued many times by many people on many forums. Here is one example, posted elsewhere but by someone who is a member here:
Icemud420 said:
There is a relationship between temperature, CO₂ levels, and the amount of light-energy that a plant can actually process. Above a certain amount of light (varies), you're not going to see any benefit at ambient CO₂ and average grow room temperatures - and you'll have reached the point of diminishing returns well below that; achieving the maximum production from a given space is all well and good, lol, but once one reaches the point of diminishing returns, it can be more productive to increase the size of the grow space and spread the light out instead of merely continuing to add more light into the same space (although it is true that far more people grow with too little light for their space than too much). That study obviously did not take DLI into consideration, since the people performing it were only giving the plants light for very short periods of time when measuring things, instead of throughout an entire 24-hour period. Mexican sativas require a lot more light than a 100% indica (or the majority of hybrids) - had they used a pure Afghani, for example, they almost certainly would have ended up with lower numbers. Et cetera.
I cannot claim to understand every nuance of that study. But I did learn a lot more after reading it (more than once) than I did from looking at the extract. AND... Those Internet forum discussions that some don't seem to think much of also added to my knowledge, lol, because some pretty intelligent people were nice enough to take the time to explain things in layman's terms. And, since someone used the term "peer review," well... Often (sadly, not always), when incorrect information is posted on a cannabis forum as being factual, sooner or later someone will wander into the thread and call, "Bullsh!t." Because many of the people that frequent cannabis forums... grow cannabis - and a lot of them have been doing so for decades - and not all of us are of the "this worked for me last time, so it MUST be the best way to do it" mindset, and are always looking to learn how to improve, if not for our own production, at least because we like to learn things. I'd sort of consider this to be peer review, LMAO.
EDIT: But if you're only interested in growing a specific (unnamed) Mexican strain of cannabis, are only interested in growing leaves, and don't plan on giving your plants more than 45 minutes of light at a time, lol, then that study might have all the data that you need....
PurpleGunRack
Well-Known Member
Thanks for that Tortured 
The not so easy to understand parts of the study seems to be like that on purpose to sound clever, rather than being rooted in a profound understanding of cannabis and light.
Funny to read the qoute from Icemud, I was thinking all these things while reading it
I'm looking forward to seeing some of those 45 minute strains
There are some good side by side grows on RUI
The not so easy to understand parts of the study seems to be like that on purpose to sound clever, rather than being rooted in a profound understanding of cannabis and light.
Funny to read the qoute from Icemud, I was thinking all these things while reading it
I'm looking forward to seeing some of those 45 minute strains
There are some good side by side grows on RUI
Well, we have to remember that they weren't publishing for the layman. A couple physicists carrying out an experiment about quantum mechanics (or even discussing it among themselves, lol) will most likely produce some heavy reading, too. I (vaguely
) remember the first time I read In Search of Schrödinger's Cat: Quantum Physics and Reality by John Gribbin, which is (more or less) written for the layman, and I kept stopping to reread sections, pages, and even paragraphs until I could manage to digest them - and that was way back in high school when I still had... well, not all of my functioning brain cells by then <WHOOPS!>, but far more than I have now.Funny to read the qoute from Icemud, I was thinking all these things while reading it
He has a LOT of knowledge about LED technology, that's for sure. As do you, it appears. (Thank you for sharing it with us!)
Thanks for that Tortured
The not so easy to understand parts of the study seems to be like that on purpose to sound clever, rather than being rooted in a profound understanding of cannabis and light.
Funny to read the qoute from Icemud, I was thinking all these things while reading it
I'm looking forward to seeing some of those 45 minute strains
There are some good side by side grows on RUI
What is RUI?
Stunned
Well-Known Member
I'm thinking it's another cannabis forum that we probably can't mention otherwise the mods will have a bird
switch the U and the I around
switch the U and the I around
PGR, you seem to know a little something about lights. My first grow I used garbage blurples by necessity - 2 1200 watt Maxisuns. 120 ten watt diodes each. Complete GARBAGE. I just upgraded and am eagerly awaiting delivery of my G8 C3 Enhanced Full Spectrum LED with flower booster. Are you familiar with this light? It's their top of the line and it compares favorably with the Gavita 1700e, which was my first choice. But to have to pay so much extra for the controller and EVERYTHING is sold separately - I couldn't do it. So after much research I decided to try this G8. Their high end blurple garbage was highly rated for blurples and they are an American company with all the right diodes and such. So we'll see. I have a separate post somewhere on here asking if anyone has experience with this light. Anything you may know would be appreciated!Re: Plz help me understand this umol's/par
If you're on a tight budget getting HID is the way to go, you can even find used reflectors and ballasts and just have to spring for a new bulb.
If you're looking for the best the market has to offer at the moment you have to do a DIY build(or kit assembly) with strips/boards using the Samsung LM561C diode or the new Samsung LM301B diode. If you want to learn more about DIY, follow the link in my signature
Also, if you CAN grow with more light, why wouldn't you? Light = dense. Light = yield. Light = EVERYTHING.
Just my inexperienced opinion.
Here is a writeup that I did a few years ago which explains plant lighting the best that I could. It covers PAR, PPFD, DLI and other concepts for plant lighting. Its definitely going to answer most questions you need to know...
Icemud LED Grow Featuring The All New Budmaster COB Technology - White Full Spectrum
Icemud LED Grow Featuring The All New Budmaster COB Technology - White Full Spectrum
Thank you so much for this detailed response and for taking the time to respond at all. Us newer growers really appreciate it when those with much more experience are so willing to share their knowledge. And you were right, the article DID answer most of my light questions. But not all. I have some questions regarding the idea of "bringing the lights up slowly to 100%" under various circumstances. And assuming one would usually not run their quality lighting at 100% for early seedling/veg (for example), I am curious about the best way and timing to get from the say 60% power to 100% when bringing the lights "up" as veg progresses. Do you have anything on that? Also, I understand that I am not allowed to specify other specific light brands on your post, which I obviously understand and respect. Regarding the light you reviewed here - The corner drops and side drops on the ppfd chart would be concerning to me. But that is nothing more than a statement from someone who is just now awaiting delivery of their first "legit" light. Is there some place that I can ask you about a specific light comparison without offending anyone? If so I would really like to do that. I also have some strain specific questions to ask about strains I am about to grow for the first time but which I'm pretty sure you will have grown before. What would be the best way to discuss/ask you a few questions about that sort of thing? I am super impressed with your grows, your honestly and transparency, your base of knowledge, and seemingly your philosophy of growing as well. I believe the philosophy part is important.
Anyway, thanks again, and thanks in advance for any responses you may have to the above.
PS - I have attached three pictures from my first (and only) grow. The strain is Surfr Seeds version of Pineapple Upside Down Cake. Technically Golden Pineapple x Wedding Cake F2. It was a tall plant that I let overtake my tent due to a plethora of rookie first time grow mistakes. That said, considering this was by necessity a cheap blurple grow and was my very first one ever, I was pretty pleased with the results. I harvested 10 1/2 ounces of buds that looked like the finished bud in the picture and a couple ounces of flarf. Which honestly is terrible and I would be very bummed if I ever messed up enough to only pull that from any grow in a 5x5. Lol.
Grower2020
Well-Known Member
So I've had my light much too high for pre flower and start of full flower. I've had it up at about 82cm above the top of the canopy which has been giving me about 650ppfd at canopy height. As soon as I read this I went to the tent and lowered my light down about 20cm . I'll slowly lower it more over the next few days .
you can not calculate what the ppfd would me at 16 inches .. it must be measured!!!!!!!!!!!!!!!!!!!! with a par light meter
u can buy.. try lowering your lights 26 inches is high above canopy in a home grow..
cheers
too many basic question by this guy needs to watch you tube videos to learn some shit..
