Investing in new lights LED or HID?

[secondtry]

Hey Mad,L.,

makes sense 2nd, but why not just present LED as appropriate for power restricted scenarios (self-imposed or otherwise)?

I agree, and that is how I present LEDs, see my sig

There's a bit of a tendency to give them negative emotional weight in you posts. Sure, it may not be as good as HPS, but in my book, THAT is not as good as the sun.

I disagree:

SPD, i.e., spectral quality:

HID is very similar to the sun if using something like a Hortlilux blue or CMH (in terms of spectral quality, i.e., SPD). The PAS (Photosynthesis Action Spctra) of plants is the same under sun and HID (i.e., bright white light), thus if we use a lamp with a 'good' SPD we can offer very close to the same spectral quality (i.e., Quantum Efficiency) as the sun. Note: I think CMH won't emit enough PPFD that is hwy I choose the 1,000 watt Hortlilux blue vs. 400w CMH (but I need to test with PPFD meter to be sure).


PPFD, i.e, irradiance:

The sun emits about 1,500-2,000 PPFD near equator at sea level around noon in late summer on a clear day. And the sun emits about 200-400 uW/cm^2 UV-b as a peak around noon in the same region of the world (also at high altitudes of around 7K+ feet elsewhere in the world). As I have shown 1,500 PPFD is about ideal irradiance for cannabis, and that's the same irradiance as the sun emits. That is why I am buying a 1,000 w Hortlilux Blue: to reach 1,500 PPFD.

Thus:

We can offer very near the same SPD as the sun, and the same irradiance as the sun in terms of PPFD with an HID and UV-b.
​

there's always something that is in some way better, because every choice is about weighing relative advantages and disadvantages, no?

True.

So helping me make my long term plans is about making sure I understand all the strengths and weaknesses, so that I can compare those to my actual situation and place.

Yes, that is what I have been trying to do. I never once wrote something like "LEDs dont' work", or "LEDs can't grow cannabis". However, I see no reason to use LEDs unless one is in a power-limited environ or a space limited environ like a cabinet grow (which IMO is a waste anyway).

In situ, btw was a good word for NT to choose. It implies so much in the scientific sense, but especially something about place in the art of living sense.

No it's not. He should have used in vivo because in situ is half way between in vitro and in vivo. We want in vivo studies for real-world applications.

All the best

 

[secondtry]

Hey Mad.L,

bro she's trying to make a living. would YOU write you back?

Umm, yes. She and I were having a nice conversion until she decided she didn't want to talk anymore and she removed all my posts. What I was writing was too true for her I guess, and she was beyond her depth of understanding (apparently). There was no animosity between us. And yes, I would have told someone what kind of equipment I plan to purchase if I has bragged about it like she did. There is no reason for her not to tell me what she plans to buy considering she told me she is buying something and I better know that, but she wouldn't tell me what she is buying...that's suspect to me.

She could be using the time chasing a sale or troubleshooting for customers instead of arguing with some guy who will never buy her product, and is convincing others not to buy her product.

How about she TESTS her product before she sells it? Is that too much to ask? All I want LED sellers to do is test their panels with Li-cor PPFD meter and present the info, how hard is that? (IMO they don't do it because they know it will show how inferior LEDs are to HID in terms of PPFD).

There's a bit of a sense that these early sales are funding the process of tweaking the technology, but many MJ growers are willing to take the risk. What's more, you can still grow a crop with 63w LED array from LEDgirl that will pay for itself in 3 months if the product is sold in the northeast US.

it only costs about $900 to buy the PPFD meter and readout hand-held I am buying. She should have already done so.

Why grow inferior cannabis with LEDs when one can grow better cannabis with HID (when used correctly)? It's risk/cost ratio: why risk jail time to grow less then ideal cannabis with LEDs when one can use HID?

re: photos, I don't think photos could make your point. just analysis.

Thank you! Neither do I. While pics are nice they tell us jack shit most of the time.

One thing though, isn't a greenhouse different in many ways from a typical indoor grow? Humidity, (filtered) real sunlight, etc...?

No, not enough to make the data invalid (assuming you mean the greenhouse from the studies). The PPFD, Co2, VPD, temp, etc, etc, was quantified and reported. The data they reported pretty much matches what we should try to achieve in an indoor grow in terms of PPFD, Co2, VPD, temp, etc, etc.


All the best, thanks.

 

[mad librettist]

thanks, it's all very informative 2ndtry.

Just consider though, that I have spotted some emotional language (words like sub-par, inferior, etc...) that can push some people away or distract people so they have a fight with you. They may not be emotional to you, but they are for me and others.

I'm sorry LEDgirl didn't give you the info. Remember though, there is always a story on the other side. One where you are wrong instead of her.

I'm thinking I would maybe like to grow buds of ok quality (but not as good as HID) in order to get my power use down. I used to guerilla grow, with minimal environmental impact. Now I am burning 475 watts in a rubbermaid.

As for the sun, bullshit! Ain't nothin' like the sun. Can HPS tuned right with UV make you more cheerful just by looking at it, or even standing under it blindfolded? There is something about our sun that can't be replaced or duplicated. I don't need any instruments other than my own body to tell you that. Weed, tomatoes, whatever they all taste better under the sun, and they all taste better after a sunny season (as opposed to cloudy and damp).

Just as you say LED is only good if you are power restricted, I say HPS is good only if you are sun restricted.

 

[NiteTiger]

I said it earlier, should have stuck with it, you're not worth it.

 

[mad librettist]

NT, it's not so cut and dry. I was the same grower/gardener I am before I started putting up pics. And I got treated like a blowhard until I did. However, the pics I post are not a result of learning how to garden, but of learning what an F-stop is, and how to adjust shutter speed, exposure, etc... I still suck at it. But I've always been good at gardening, and my info hasn't changed anymore than it normally does over time. Pics don't mean I know what I'm talking about, they just mean I have pics of a grow. Maybe it's enough to make someone pay attention, but you have to go by the merits after that.

That's what keeps us from being gullible.

2ndtry has some great ideas, always useful even if you disagree. He just gets a bit overzealous and frustrated, like we all do from time to time. He is not an asinine twit, and you aren't whatever he called you.

You guys should think of the rest of us. Your conversation was teaching us loads until it got personal. I'd love to hear more. And it really is as easy as just putting down the brass knuckles and talking.

 

[secondtry]

UV-b irradiance:​

I asked someone to review my math and he found a big error. Below is the corrected math. The funny part is his result was the same as my first result (i.e., 124 uW/cm^2), but I thought it was wrong so I redid my math (incorrectly the third time).

If we are copying the work of Lydon, et al,. (1986) we would use a 3 hour time frame of UV-b irradiance at ~124 uW/cm^2 as measured from a UV-b meter like the SolarTech 6.2. For a 1.5 hour time frame of UV-b irradiance we want 248 uW/cm^2. For a 6 hour time frame of UV-b irradiance we want 62 uW/cm^2. I will probably use 100-150 uW/cm^2 as a goal (possibly avg. over whole footprint) for 4 hours a day, or considering hot spots I may use 60-200 uW/cm^2 as a range for the footprint of irradiance for 4 hours a day. Basically I am trying to reach 300-400 uW/cm^2 of total UV-b in less than four hours each day.



(the following data assumes the absolute uW from both the a SolarTech 6.2 UV-b meter and the spectroradiometer used in the study are the same and it's probable they are not, thus this data is a close approximate)

Here is the correct math:

1. (13.4 kJ/m^2/3hr) / 3 = 4.47 kJ/m^2/hr

2. (4.47 kJ/m^2/hr) x 1,000 = 4,467 joule/m^2

3. (4,467 joule/m^2/hr) / 3,600 = 1.24 joule/m^2/sec

3. 1.24 joule/m^2/sec = 1.24 watt/m^2

4. (1.24 watt/m^2) x 1,000,000 = 1,240,000 uW/m^2

5. (1,240,000 uW/m^2) / 10,000 = 124 uW/cm^2​

Thus:

(124 uW/cm^2) x 3 hours = 372 uW/cm^2/3hr as the total daily irradiance of UV-b​

Or:

(248 uW/cm^2) x 1.5 hours = 372 uW/cm^2/1.5hr as the total daily irradiance of UV-b
​

Or:

(62 uW/cm^2) x 6 hours = 372 uW/cm^2/6hr as the total daily irradiance of UV-b​

 

[secondtry]

Hey Mad.L,.

Mad.L wrote:

Just as you say LED is only good if you are power restricted, I say HPS is good only if you are sun restricted.

^^ haha, classic. I agree 100%.

2ndtry...just gets a bit overzealous and frustrated

Guilty.

Mad, L wrote:

You guys should think of the rest of us. Your conversation was teaching us loads until it got personal. I'd love to hear more. And it really is as easy as just putting down the brass knuckles and talking.

I am willing, I had no beef before the UV-b talk. I agree I can be an ass, but not when unprovoked. I agree it's water under the bridge, as long as things don't continue as they were.

Thanks

 

[NiteTiger]

2ndtry has some great ideas, always useful even if you disagree.

I never said I disagreed. I actually said, frequently, I enjoyed the information.

I disagree with the way he presents it, and I feel he is being purposefully disingenuous in the way he is presenting his information.

I won't see his posts any more, so it won't effect me in any way, but hopefully people will see this, and know to take a second look at what is being claimed or implied.

That is as far as I'm willing to go as far as 'thinking of the rest of [you]', I'm not going to sit and let myself get agitated over something this ridiculous any longer.

 

[mad librettist]

I am willing, I had beef before the UV-b talk.

try some daikon radish soup with bonito stock and tofu and some kind of seafood. have a wakame and cucumber salad on the side. I can PM you directions to make a great smoky vinegar dressing for that. that should be very cooling.

beef makes me agressive too.

NT, just try again. If you don't practice...

I've been in this same spot with 2ndtry, probably will be again. It's the recovery that's important.

Plus think of all the people who agree with you. However many that is or isn't, you are expressing something for them.

 

[secondtry]

Mad.L,

Haha, you got me before I could edit "had beef" to "had no beef", as in I had no problem with NiteTigher before the UV-b talk. Like you wrote, it's the recovery...

 

[Zombo]

Depending on the conversation I'd like to have with LEDGirl, I will possibly submit the 126w Penetrator I purchased today for testing. I may or may not post the test results myself, what secondtry does is his business.
That said, the reason I wish to ask LEDGirl about this is because I have a good business relationship with her now (having purchased two units) and will not jeopardize that if it stirs up shit. Should secondtry *really* wish to put his money where his mouth is, he would BUY a unit from her and test it. Then publish his results.
Proof for me, at least as far as the 63w unit is concerned, has been in the pudding, i.e., the buds I am growing with it right now. All the numbers, graphs and charts are a fun read (I studied this stuff in college) and I do respect the efforts put into gathering that data, but once again, balancing out ALL factors into my needs, LEDs are a perfect solution for me.
What many HID exclusive growers who are trying out LEDs are discovering is that the techniques, footprints and environmental variables have to be tweaked and adjusted to maximize yeild, they're not a simple "drop-in" replacement.

 

[NiteTiger]

ML: See, that's the problem - there is nothing to try again. My issue was always in the presentation, and I have tried repeatedly to make that clear.

2nd can't understand what I'm saying, and sees no issue.

There is clearly a disconnect, and we can't communicate effectively because of it, so there is nothing to be gained from trying again.

I've put my objection on the record, so to speak, so that it is available to any who read the information. Those readers will have to take from it what they will.

Que sera, and all

 

[mad librettist]

Now how about we talk about LED vs. HID

What if we were to think of a scale from 1-3 for the characteristics of a light source (Sun, LED, HID):

Ease of concealment (eyes and ears and power company and law enforcement)
Cost to operate (environmental)
Cost to operate (monetary and effort)
Initial cost
Effect on growth and quality
Yield possible per square foot


what else?

 

[Zombo]

Now how about we talk about LED vs. HID

What if we were to think of a scale from 1-3 for the characteristics of a light source (Sun, LED, HID):

Ease of concealment (eyes and ears and power company and law enforcement)
Cost to operate (environmental)
Cost to operate (monetary and effort)
Initial cost
Effect on growth and quality
Yield possible per square foot


what else?

How about a 1 to 5 scale and you sum the points for the categories?

I'd also add "Ease of implementation" to those.

 

[ocean99]

I'd be pretty angry if I shelled out the cash for an LED system in 2010, only to have twice as good technology come out a year later for half the price....

 

[mad librettist]

How about a 1 to 5 scale and you sum the points for the categories?

I'd also add "Ease of implementation" to those.

sounds like you know what you are doing. can you take over? I'm getting anxious about the task.

 

[Zombo]

sounds like you know what you are doing. can you take over? I'm getting anxious about the task.

Perhaps I will start a thread on it.

 

[mad librettist]

cool.

 

[Zombo]

I'd be pretty angry if I shelled out the cash for an LED system in 2010, only to have twice as good technology come out a year later for half the price....

Isn't that the same with any new and evolving technology?

 

[secondtry]

Hey Zombo,

Depending on the conversation I'd like to have with LEDGirl, I will possibly submit the 126w Penetrator I purchased today for testing. I may or may not post the test results myself, what secondtry does is his business.
That said, the reason I wish to ask LEDGirl about this is because I have a good business relationship with her now (having purchased two units) and will not jeopardize that if it stirs up shit.

No worries, I don't want to cause you any problems.

Zombo wrote:

Should secondtry *really* wish to put his money where his mouth is, he would BUY a unit from her and test it. Then publish his results.

That is what I plan to do, but I am already putting my money where my mouth is by spending about $1,000 on the PPFD meter setup. Once I have a spectroradiometer I want I will publish my own SPD for each lamp I test, and I will use PPFD as the irradiance axis on the graph with the Photosynthesis Action Spectra (PAS) behind the lamp SPD.

I offered to test lamps to get it done quicker. I plan to buy a 300w unit from LEDGirl to put this topic to rest. But that will take a more than a month.

Zombo wrote:

Proof for me, at least as far as the 63w unit is concerned, has been in the pudding, i.e., the buds I am growing with it right now. All the numbers, graphs and charts are a fun read (I studied this stuff in college) and I do respect the efforts put into gathering that data, but once again, balancing out ALL factors into my needs, LEDs are a perfect solution for me.

That's great. However, I have not tried to imply, nor have I written LEDs like the kind LEDGirl sells do not grow cannabis. My problem is the claims made by LEDGirl and other LED sellers, i.e. comparing them to HID using lux to PPFD, etc, and no one testing lamps themselves. I state HID lamps with good SPD used correctly (ie., PPFD) is better for cannabis than LED considering the technology of LED panels today and I assume as it will be for many years to come. If growing in a space where heat or height is a problem LED can be a solution for sure, but LEDs won't grow cannabis like HID will grow cannabis (in terms of PPFD).

What many HID exclusive growers who are trying out LEDs are discovering is that the techniques, footprints and environmental variables have to be tweaked and adjusted to maximize yeild, they're not a simple "drop-in" replacement.

I totally agree. However PPFD is the most important comparison factor, the growing method is irrelevant when comparing with PPFD. Either a lamp or LED panel can reach 1,300-1,500 PPFD at a usable distance (e.x. > 8-10"), or not. If not then the LEDs or lamps (e.x. a 400 watt) should not be claimed to be as good as lamps that can emit 1,300-1,500 PPFD (although one wants a good SPD, that is why I am going to test the Hortilux Blue 1,000).

What this boils down to is the question I often see: "will 300w LED panel beat a 400w HID?". That is not a real question because plants don't use watts to drive photosynthesis, they use photons within PAR range for a vast majority of photosynthesis. If we test lamps and LEDs with a PPFD meter there is no conversion of data, PPFD is an accurate way to compare lamps and LEDs. And because PAS does not have large peaks between blue, green and red photons the SPD of the lamps and LEDs are less of an important factor. PPFD is the way to go. Ideally we would weight PPFD from each wavelength with the relative ability of a photon within each of the PAR range wavelengths to drive photosynthesis (i.e., Quantum Efficiency).

FWIW: I am going to use "PPFDi" with quantum sensor when measuring light/plant interaction. PPFDi is PPFD of the canopy, intracanopy and bottom of canopy; thus it's much more representative than just PPFD at top of canopy.


HTH