Light meters--what rating do I need

[spurr]

My dear spurr,

I don't want to argue with you, nor do I intend to change your mind.

We are not arguing. We are having a pleasant debate that others can learn from. My only goal was to make the comparison even, not to 'stack the deck' as you inadvertently did with your oversimplification of the issues.

And you may very well change my mind. As many here can attest, I am very open to being wrong. In fact, I like being proven I'm wrong, so I can then become right (correct). I for one do not want to be wrong, so I thank those that educate me. However, you have not yet done so ...

However in future please keep in mind that most people have no interest in being absolutely accurate, just getting the job done.

Please stop assuming you can speak for most growers. You cannot, nor can I.

It must be awfully lonely in your ivory tower, so sad for you as the rest of humanity is doing just fine with playing scientist.

Well, so far from my "Ivory Tower" (as you try to disparage me), I have done more for the cannabis community wrt killing myths and helping people grow better, then nearly all other growers. Most certainly more than yourself. All growers that wish to do so, may benefit from my work in my Ivory Tower, not all growers have your mindset and attitude .

Hope someday your mind may actually be open enough to hear someone else's ideas without resorting to defend your own.

Pot ... kettle ... black .

And of the two of us, I would hazard a guess that I'm far more open and willing to be wrong. At least I bring data and proof. You bring hyperbole, logical fallacies, non sequitur and assumptions of how lazy and apathetic growers are.

PS I'm a retired IEEE fellow who designed nuclear imaging for a very large German Engineering corporation. I have probably forgotten more than you'll ever learn, particularly with a closed minded attitude.

Such laughable claims allow your true colors to shine through. Why not post data and proof, instead of throwing shit like a monkey?

You won't have me bothering you since you already "know it all".

Great, thanks for that. And it's nice to see you think so highly of me ... BTW, can you say: BURN?!

P.S.
I'll do you the same favor and won't respond to you again. I assume you will want the last word.

 

[spurr]

@ All,

Considering we are discussing light qualification and quantification, I thought I would post a bit of my plans:

My next big project is a DIY "Ulbricht sphere"[1] , aka, "integrating sphere". However, I dislike the term "integrating sphere" (instead of "Ulbricht sphere") because integrating spheres are also small things we use with leafs[2] to find Quantum Yield Curve, re photosynthesis and photons; something I have planned too, so I will make the first Quantum Yield Curves for cannabis, re K.McCree!!!

[1]

[2]

​

Using Ulbricht sphere is how lamp companies provide lumen and/or PPF rating for lamp. They are quiet easy to build, to provide high accuracy and reliability on par with commercial models that are many tens of thousands of dollars. The trick is using the correct shape and reflective paint (e.g., "Spectrolon").

Once I build my Ulbricht sphere I will buy a good OceanOptics spectroradiometer (from UV-b to IR) for ~$5,000, as well as a few (more) Licor terrestrial and underwater quantum sensors (which are not used under water in our case). That is, until I can afford a really good spectroradiometer for > ~$50,000, such as the OL-576 spectroradiometer from Gooch & Housego, i.e., very low % stray light, scanning double-grating monochromator and high signal:noise ratio above 300. Then it's on like Donkey Kong! I will start testing the shit out of everything I can get my hands on

Oh yea, I'm making the Ulbricht sphere large enough so I can put whole luminaires inside, not just lamps! I may make two U.sphere's: one for lamps and one for lamp + luminaire (reflector).

 

[sunshowers]

Originally posted by spurr

I have done more for the cannabis community wrt killing myths and helping people grow better, then nearly all other growers.

Such humility !!!

 

[spurr]

It's called a fact. Please, disprove me. See what I explained on an earlier page.

@ all,

If you have nothing of value or substance to add, like our good friend sunshowers, please do not post.

And LOL at the person who gave me a negative rating for my post about my plans wrt Ulbricht sphere and making the first Quantum Yield Curve for cannabis. How is that bad? (that's rhetorical, please don't waste your last brain cells trying to form things we call "words" and "sentences").

 

[Weezard]

Intelligence flees from anger.

Intelligence flees from anger.

"please don't waste your last brain cells trying to from things we call "words" and "sentences")."

Um. Irony!
Don't write well when pissed, eh?

"helping people grow better, then, (sic), nearly all other growers. Most certainly more than yourself."

Extremely incorrect my friend!

While I appreciate your personal need for extreme accuracy,
For some of us, it is simply not necessary for growing superior meds.

That is just one of my opinions.

Hempyguy is IMO a very helpful member here.
You could learn a lot from him.

While you are very busy splitting hairs, Hempy is actually helping, po' folk grow and has been helping this community, for almost a year, on this board.

"In theory, theory and practice are the same thing.
In practice, they are not!"

When it comes to a growing mentor.
I will go with talent over tools, almost every time.

More plainly.
A natural scout, needs no compass.

With some of us, it's a "feeling".
Your plants will try to tell you what they need.
But you must learn how to listen.

(Or perhaps it's an inborn talent that can be awakend but not learned. I don't know.)

I do know that Hempy has helped me to be a better grower.
And if I should misplace my admittedly shoddy compass, I will still be a good grower, because he helped teach me to "feel" my grow without tools.

Believe it or don't. there is a "link" between all living things.

For those who have yet to feel this link, there are wonderful tools available.
Should I ever have an actual need for that high a level of measurement accuracy, you would be my "goto" guy

So please do not go away mad.
There are plenty folks here who, lacking the "feel", must have tools to grow successfully.
Those folks can't get by on cut and try.
They will use and appreciate your guidance.

Me, I just read you because I enjoy learning.

Aloha gentlemen.
Carry on.

Weezard




.

 

[spurr]

"please don't waste your last brain cells trying to from things we call "words" and "sentences")."

Um. Irony!
Don't write well when pissed, eh?

Um, no. You must type VERY slowly, eh? Because I fixed that typo about an hour (58 minutes) before you posted .

"helping people grow better, then, (sic), nearly all other growers. Most certainly more than yourself."

Extremely incorrect my friend!

Well then, you haven't read enough of my writings . And I'm not about to get into a pissing match with you wrt HempGuy, but I will say I'd bet all i have that your opinion is not the majority here. No one has killed more myths than I have, it's not my fault they just won't die.

You could learn a lot from him.

Possibly, but I have highly doubt it. That said, I would be very willing to learn from him if I can. However, in this case wrt this thread, he's dead wrong. As I have written many times, you CAN use a Lux meter but it's far from ideal. And anyone who disagrees with that statement is simply ignorant of the issues or is being disingenuous. That's a fact, not my opinion.

The big issue, IMO, is most people don't want to believe they aren't doing things correctly and/or to the best possible degree.

We (probably) only live once, it's important to not do anything half ass, well, anything that's worth doing ...

While I appreciate your personal need for extreme accuracy,
For some of us, it is simply not necessary for growing superior meds.

Please stop assuming you can speak for all cannabis growers, you cannot, nor can I. Unless by "us" you mean you and HempGuy. And it is necessary if you want the most superior meds, yield, growth, plant health, etc. People spend so much time on genetics, hydro, CO2, fertilizer, blah, blah, blah, but they forget (or don't fully understand) the very critical issue of light (and that includes folks in the LED cult, such as yourself).

That is just one of my opinions.

I'm quite surprised to see you post this, we have always been friends online, even when I helped you via e-mail wrt the LED company I was helping with their product about a year ago . But now, because of your 'out of left field' post to me, that shit's over.

While you are very busy splitting hairs, Hempy is actually helping, po' folk grow and has been helping this community, for almost a year, on this board.

I'm not spitting hairs, I am getting out facts you seem to wish were not facts. And stop assuming no one cares about these issues just because you do not. To assume that makes you foolish, just like HempGuy.

"In theory, theory and practice are the same thing.
In practice, they are not!"

When it comes to a growing mentor.
I will go with talent over tools, almost every time.

More plainly.
A natural scout, needs no compass.

With some of us, it's a "feeling".
Your plants will try to tell you what they need.
But you must learn how to listen.

(Or perhaps it's an inborn talent that can be awakend but not learned. I don't know.)

Please don't assume you know anything about me, I'm not about to divulge personal info here but suffice it to say, you are preaching to the choir.

I do know that Hempy has helped me to be a better grower.
And if I should misplace my admittedly shoddy compass, I will still be a good grower, because he helped teach me to "feel" my grow without tools.

Believe it or don't. there is a "link" between all living things.

Stop effing trying to lecture me as if I don't know all of this. And BTW, this isn't a thread for you to turn into a metaphysical circle jerk.

Also, I am the first here (I believe) to bring up the topics of how to 'read' plants wrt leafs and irradiance. How else do you think I came to the irradiance data I posted? I don't yet have my photosynthesis chamber and chlorophyll fluorometers but soon I will, to verify what I posted earlier.

In case you wish to know more I will elaborate below, or you can read the "24 hour" light thread wherein I posted this info:

When plant leafs and whole plant reaches the point of photosaturation (of photosystems, which leads to photoinhibition and thus "midday depression of photosynthesis") the leafs will 'pray', esp those under highest irradiance at canopy. Leafs will also 'roll'. The reason the leafs do that is to reduce the surface area of the leaf, so fewer photons are incident (strike) upon the leaf. That way the plant can control how many photons it is getting, to a degree. Thus, if your plant's leafs at the canopy are pointing skyward (in the middle to end of day), or if the lower leafs are rolling inward, you are giving the plant too much light per day. To fix the issue reduce instantaneous irradiance (how much light per second) or decease the daylength (hours of light per day).
​

And please don't claim you can "feel" when plant photosystems are 'maxed out', because you can't. You can "feel" when a plant in unwell, but not specifics like rate photosynthesis and photosaturation, which leads to photoinhibition, lol. You silly goose!

For those who have yet to feel this link, there are wonderful tools available.
Should I ever have an actual need for that high a level of measurement accuracy, you would be my "goto" guy

First you should comprehend these issues more fully, then you can make a more informed decision and form a more informed opinion. The simple fact you don't think it's good to be accurate proves my point ...

So please do not go away mad.
There are plenty folks here who, lacking the "feel", must have tools to grow successfully.
Those folks can't get by on cut and try.
They will use and appreciate your guidance.

I'm not mad, but I am a bit annoyed that you acted this way to me, after all the time I spend helping you in the past. Also, stop effing assuming so much about growers and people on this forum. Really, it makes you look very foolish.

 

[rives]

I didn't mean it come across that way, and it didn't dawn on me that it could be construed that way. I will try to not come across that way in the future

Holy cow, Spurr, and you were making such progress!

I'm not mad, but I am a bit annoyed that you acted this way to me, after all the time I spend helping you in the past. Also, stop effing assuming so much about growers and people on this forum. Really, it makes you look very foolish.

I have never seen Weezard be offensive in the slightest, and I have a difficult time believing that was his intent today. You seem to be even more tightly wound than usual - perhaps a sampling of your superior med's might be in order! Calm down, buddy.

 

[spurr]

Ha . Eye of beholder my friend, eye of the beholder. And yes, he was being rude, so I treated him in kind.

 

[Weezard]

Oh dear! Who poked the bear?

Oh dear! Who poked the bear?

Everything is an argument with you, yah?
All "them vs. us"?
That's too bad.

Of that entire barrage of crazy, this is the nuttiest part;

"even when I helped you via e-mail wrt the LED company I was helping with their product about a year ago "
"after all the time I spend helping you in the past."


Not me, brah!
Sounds like Khyberkitsune.

Rational discussion is just too difficult with you.

Please put me on ignore.

Respectfully.
Weezard
A wise man is superior to any insults which can be put upon him, and the best reply to unseemly behavior is patience and moderation. -Moliere

 

[spurr]

Liar. I still have the e-mails.

Please put me on ignore.

Done.

 

[Rukind]

Wow people are very disrespectful in this thread. I think some of you guys need to pay more attention to spurr. he puts a lot of work into this stuff. Some people like to know the science behind these things and I find scientific proof is very lacking in the cannabis community.

Be thankful someone puts this much effort into this. you could learn a lot from him.

Too many people using generalizations and thinking they speak for everyone.

 

[tenthirty]

Spurr,

FWIW,
After many months of testing with my quantum sensor I find these values are pretty much ideal:

~800-1,000 umol/area^2/second for veg, early-flowering and full-flowering (when daylength is > 10 hours; this has to due with Daily Light Integral, see this thread wherein I posted much info on the topic wrt cannabis, etc.)
~500 umol/area^2/second for seedlings (this produces VERY compact seedlings, no stretch and big leafs)
~100 umol/area^2/second for cloning

Ok, so considering that you have the quantum sensor and I/we don't, and you are the quantum mad scientist.

Could you do some experiments and give us the appropriate distances vs bulb, watts, etc done with your quantum meter?

For most of us, knowing the average ranges would be very helpful.

 

[spurr]

Hey tenthirty,

Yes, that is my plan. And then I will release all data to the public, for free. But it's not going to be an over-night process. I believe I posted images and a link to the work of Sanjay Joshi, Ph.D, et al., that is the methodology I will copy. I am going to contact Dr. Joshi sometime in the next few weeks. However, before I can copy his method I want to get the underwater quantum sensor he used (it provides better measures for reflected photons from walls), I only have the terrestrial version now. The underwater sensor is like ~$800.

I wish I could give you an easy-to-use, black-and-white answer, but that's not possible. The main reason is irradiance (e.g., photons hitting a canopy 1 or 2 feet below the lamp) is HIGHLY nonuniform. That means the irradiance (e.g., photons per meter^2 per second) in the 'hot spot' is much higher than irradiance outside of the hot spot in the same meter^2 area. So I cannot give you one distance for X irradiance and call it sufficiently accurate, in fact, no one can regardless of claims made by others in this thread. That is why I am going to use Dr. Joshi, et al., method: because it provides thorough data for the whole area and various distances, in easy to interpret colored 3D graphs.

Other issues/problems with attempting to provide a one-size-fits-all guide is that irradiance and spectrum changes as the lamp ages, as the lamp gets dirty, as the temp changes, as the power input changes (magnetic vs digital ballast), etc. That is what I have been trying to drive home in this thread: it's not as easy to measure irradiance as many here would have you believe.

However, I did take a few quick measurements under a 400 w (generic) MH and (generic) coir/coil ballast for you. The reflector is SunSystem SS2 and the lamp has been running for maybe 4 hours. There is a heat shield in place and I use a "Equalizer" hot spot diffuser, so the data won't be the same for someone that doesn't use a hot spot diffuser, but it's close enough to provide examples. I used a 5 second measurement 'time frame', which means my data logger averaged photons per second over 5 seconds; that is kind of short for magnetic ballasts that have much "flicker", normally I like to average over 30 seconds to account for flicker from magnetic ballasts for higher accuracy:

~100 umol/~2"^2/second = ~2.5 feet (under lamp in the hot spot)
~500 umol/~2"^2/second = ~8 inches (under lamp in the hot spot)
~800 umol/~2"^2/second = ~2 inches (under lamp in the hot spot)

 

[spurr]

Oh yea,

The 400 w (generic) MH lamp I used is not new, it has maybe 500-800 hours of use so far, give or take. And that affects the irradiance data. When we test lamps it's best to test them when brand new and then when they are 100 hours old (give or take), and it's important to test them after they have 'warmed up' for a sufficient amount of time (e.g,. 30 minutes for old school lamp and ballast).

 

[spurr]

Some people have asked me what "wrt" means, it means "with respect to". It's just short hand to make typing faster. If people read words I post and they don't know their meaning, it's easy as pie to use Scroogle (or Google if you must) to learn what they mean.

 

[knna]

Spur, respectfully, I feel you are losing the perspective.

The way you plan your experiment is of your own, and if you share them on a thread open for you, it is very appreciated for many people.

But if jump on a thread asking for what light meter range is required for simple tasks as lamp positioning and checking degradation rate with so many topics off the purpose of the thread, it is completely useless, and worse, in some sense you are hijacking the thread. And when you use each small disagreement with your opinions as the opportunity of start a discussion, it means you need to stop and look at yourself.

Calm down, man, you are lately running at excess RPM.

 

[spurr]

Spur, respectfully, I feel you are losing the perspective.

No I am not. I feel you're confused or being disingenuous with the rest of your post.

The way you plan your experiment is of your own, and if you share them on a thread open for you, it is very appreciated for many people.

No it is not, not if a well proven method is already laid out by a highly respected Ph.D physicist. However, if you you want to make tests with unproven methods and half-assed results, be my guest.

But if jump on a thread asking for what light meter range is required for simple tasks as lamp positioning and checking degradation rate with so many topics off the purpose of the thread, it is completely useless, and worse, in some sense you are hijacking the thread. And when you use each small disagreement with your opinions as the opportunity of start a discussion, it means you need to stop and look at yourself.

Maybe you need to stop and look at the first page . Wherein I already answered the OP's question, better and before your post. Thus, the OP's question was answered by me on page one, post #7 (here), long before you came in and repeated EXACTLY the thrust of what I wrote, on page 3, post #31 (here). So, your post was a waste and just parroted mine ...

Also, the only reason I posted about quantum sensors (starting here, post #6) was in response to growshopfrank's post #5 (here). So, why don't you bemoan him for posting about quantum sensors too? That is why I stated you're either confused or being disingenuous, because you're not correct (again).

Also, I just realized I made a typo. In that old study (1975) I found on cannabis and rate of photosynthesis (Pn) wrt Lux, the results found < 120,000 Lux gave lower Pn than 120,000 Lux.

"Photosynthesis and Cannabinoid Content of Temperate and Tropical Populations of Cannabis sativa"
F.A. BAZZAZ, D. DUSEK, D.S. SEIGLER and A.W. HANEY
Biochemical Systematics and Ecology (1975), Vol. 3, pp. 15-18

• I uploaded full text to this post.

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​

Calm down, man, you are lately running at excess RPM.

I am clam. And this is how I think and type: fast. Sorry you don't like it. Also, IMO, you're the one trying to drive this thread off topic, along with other people here trying to disparage me for posting facts you guys/gals don't like.


FWIW,
I hope your post is the last in this thread that tries to disparage me for posting facts, as inconvenient to you and others as they may be. Facts are funny things, you cannot make them do your bidding unless you're being disingenuous.

 

[Snype]

Thanks Spurr!

 

[TanzanianMagic]

This is just a rough measurement, however I have been having problems with growth from an old fluo setup I use for seedlings and clones, so I decided to measure some successful light strengths.

I also grow on a balcony, so I also has problems with too much light burning plants. This disappeared when I filtered the outdoor light with a light culoche, which produces great growth, from seedlings and clones to young plants.

The poor light from the fl setup was 400 lumens.
The ideal lumens I measured under a culoche was 10,000 lumens.
Full sun in July is 130,000 lumens.

I hope that helps.

 

[hot cheetos]

Why did spurr get banned????? The guy is amazing!