LED Lab 2009

[knna]

Knna my friend, it isn't often in this environment I feel I can make a worthwhile suggestion, but this is one issue I think I can definitely help with.

Simply take a measured sample from each test crop, use bubble bags and condense into hash, the hash can then be definitively weighed, and since the hash is in all reality the thc trichomes and glandular stalks you should have a very accurate method of measuring thc content.

Thank, Leo. I already have thought on it.

But there are so many types of extraction methods that I think is going to be very difficult to standarize one. And if we manage to do it, still the variation is going to be reaaly large. Some people use cool water, some people iced water, some process yield 1 time, some 3.

The real problem of any extrantion method is that the product is very small and light compared with the starting product. In this context, very small errors account for a very large percentage. So its very difficult to have consistency on resin extractions.

But its not only that. If we really want to study resin, it should include cannabinoids profilling. As very little growers have the tools for it, it should require complicated logistics (and safety concerns) to do it.

So I think its going to require that some individuals does really controlled studies of it.

We have talked on the spanish forum about using Cannalyze (I have one, but I need to get new solvents and plates) to the profilling, that although is not an high precission method should offer enough info, specially when doing comparative analysis (what changes at given light qualities). People will send me samples of hash and weight their extractions (we have talked about using butane extractions as more accurate) and I profile the samples. But Im not sure it gives us the answers we are looking for.

Ive though too of using a vaporizer to evaporate cannabinoids and weight buds used after and before it (probably, some measurements after given periods at each temperature). I think this should offer the best accuracy, but a very precise weighting scale should be required. At least for THC, it should work pretty well, due at temperatures below combustion point it has evaporated almost completelly.

But if any of you have an idea, please share it. No matter if you think its cracy. Still if it is, it may give a good idea to other, or other may find thw way to convert a crazy idea into a genial one

 

[knna]

Smokingshogun, please, read again my answer.

Im taking it into account. More, Im saying any study must be based on it: mols of photons used along the grow.

It takes into account photoperiod, lenght of the grow, and if different components are on at different times.

The calculation of total mols of photons is the same than that of converting Watts installed to KWh burned along the grow.

E (mols of photons)= (uE/s)*hours on* 3600 (seconds on 1 h)

If you have different lamps at different photoperiods, you need to do it for each one and sum all. Just the same that calculating KWh.

Anyway, although I rarely use 12/12, during research Ill use it, just to eliminate a little studied factor as different photoperiods. Ill use different photoperiod on the future again, when we have answers to the basic questions.

But for different intensities, we are actually taking it into account. Most of us starts the flowering with LED lamps dimmed, and go increasing its current as flowering progresses. We anotate it, with the watts consuption and uE emission for each current level (we have separated channels for InGaN and AlInGaP LEDs)

 

[bf74]

whats up knna? WWhat are your thoughts on the current "sun-burst" orange diode tek? Oh, heres my new 100%-I've officially fully converted-led grow.The seedlings were under hps for 3 hours before I decided to scrap the hps-so their growth has been all led-well, except for 3 hours, the seedlings are 22 days from popping-vegged under 150w of led, and flowering for 2 days under the illuminator ufo's x3.I've also included 2 centrally mounted 12w 1w diode pure white fixtures.

 

[mrchris]

I would be happy to help your research.

I have 3 LED Boxes now. (Little ones)
If you want to look at. link.

 

[knna]

whats up knna? WWhat are your thoughts on the current "sun-burst" orange diode tek?

I think we have talked about it before in this thread. All the experiments adding some yellow amber are definitively increasing spectral efficiency, apart of contributing to eliminate any lenghtening of the flower time.

Currently, Im convinced that yellow is esential. The main question is how much to use.

Other related question is the way to add the yello-orange part of the spectrum. Yellow LEDs are notoriously inefficient. Below 15%, for the best of them. Currently is way more profitable to add the yellow from a phosphor converted light than from pure yellow LEDs, either white LEDs or fluorescent. Easily, double the energy efficiency.
Dischargue sodium lamps are the championships emitting yellow, so if we find that a large amount of yellow is required for an optimal spectrum, would make sense use HPS+LEDs hybrid systems.

I tend to think that the amount of yellow required is low. Most of the lamps adding yellow are using those inefficient yellow-orange LEDs. And adding a little percentage of yellow LEDs respect the total of LEDs used. So the percentage of yellow light added is being small, way below 10% and its being enough to enhance the efficacy of blue+red lamps.

As the role of yellow is growth regulation, as far as is known, and thermal dissipation of excess light, it should point that just a little yellow is required.

But...who knows

 

[knna]

Very good points, smokinshogun.

I have read that study several times, and other from same authors studying the optimal spectrums for tomato, cucumber and wheat. Full reports (larger than the resumen report you has linked, including details of lamps used, spectrum and production of each test) can be found at the NASA technical report server.

That adaptability of plant is what requires to perform long term studies (along a full grow) on each spectral quality. I have based my research on those articles. But they have some limitations.

The most obvious one is to consider three mayor wavebands, Blue (400-500nm), Green (500-600nm) and Red (600-700nm). We want, we need, to be more especific and use narrower bandwiths.

From older studies, we know more about the role of each bandwith, so probably we will need to consider other bandwiths that may differ from the results when aggregating them.

You have said about yellow, that in the study is considered part of the "Green", but that have different role. There is more bandwiths with this difference. In the "green region", there are three bandwiths, and that not fit exactly in it: cyan, that starts in the "Blue" (485-490nm) and ends in the "Green" (510-520nm), and yellow-orange, that starts in the "green" (575-580nm) and ends into the "Red" (610-615nm).

Aditionally, when studying the remaining Blue, it would be useful to split it between the near UV-violet range (380-430nm) and the pure "blue" range, (430-490nm).

For the red range, studying the differences between orange-near red (615-645nm) and deep red (645-700nm) would be relevant too, specially to decide what peak wavelenghts LEDs to use or on what percentage.

And of course, including the far red range (700-780nm)

If studing resin, two more wavebands, UVB (280-320nm) and UVA (320-380nm) should be added.

But, on the other hand, as more wavebands studied, more complex to analyze results and more difficult to reach to conclusions. Thats the reason Tikimorov et al used those 3 mayor wavebands.

I suggest to just include the cyan and yellow orange spectrum and use the other mayor wavebands, blue and red as a whole, initially.

Blue:400-490nm

Cyan:491-520nm

Green:521-575nm

Yellow orange: 576-615nm

Red: 616-700nm

(Far red: 700-780nm)

But studying the light spectrum based on narrower or wider wavebands is just a matter of the way of giving the info. Ideally, participants should use a speadsheet that caracterize the average spectrum used in each grow, in wavebands of for example, 5 or 10nm. In this way, we may process the info in several different ways.

I offer my help to do that for any grower wanting to colaborate on the research. I just need to know the LED models used, their bins and the current level (and a overview of the thermal dissipation design).

I stated many times that we must be aware of the irradiances used, so it probably affect results. And its probable than optimal spectrums varies depending of the irradiance used.

I suggest to start most experiments using medium irradiances, 400-600uE/m2 (overhead lighting only) and 300 uE/m2 (with side or IC lighting), in order to simplify things. And later, with some conclusions at those irradiances, study how higher irradiances affect.

Its important to note that at the time of the studies cited at the start of the posts (1994), side or IC lighting wasnt used. So the only way to increase production of bottom areas was using higher irradiances from top.

Currently, the potential of using IC lighting to increase bottom areas production (whole canopy photosynthesis) has been proved, so there is no need of using excessive irradiances at top canopy to increase bottom areas photosynthesis. Planophiles plant's specias are what respond the better to this lighting configurations, and we have the advantage cannabis is one of them (not the purest, but one of them). And aditionally, although cannabis buds production is shifted toward to upper areas, if the plant have enough light on the bottom areas, they produce very good bud from the bottom, as outdoor plants shows.

So in order to get great bud production, we dont need to use excessive irradiances from top, the main disadvantage of standard HID lamps configuration (fixed when using them in vertical configurations). So currently, I see little interest on study what happen at higher, suboptimal irradiances.

Notice the irradiances of the graphs posted by SS. The first compare the Inada cuve (already obtained using unsaturated photosynthesis) with low irradiances (for MJ growing) of 50W PAR/m2, below 250uE/m2, that gives an almost flat curve, with similar efficacy for all colors. The other curve is for 200 W PAR /m2, 900-1000uE/m2, that results on the strongly enhanced effect of blue. But its important to note that those curves havent an absolute scale, but a relative one, being 1 the max photosynthesis at each irradiance. Thus, blue photosynthesis isnt higher at 200 W PAR/m2 than at 50 W PAR/m2, but higher in relation to the other colors. Photosynthesis efficacy falls as irradiance raises, but while this effect is very strong for the red photons and medium for green, affect very little to blue photons efficacy.

So it should point that more blue is going to be required as the irradiance used is higher.

But this study not says nothing about stomatal conductance. We know now (not at the time of the study) that blue signal stomata to open, leading to higher CO2 internal concentration, thus making leaves able to photosynthetize at higher efficacy at high irradiances. It would be important to split this effect from the pure enhancement of blue photons, because it would be possible that when using CO2 enrichment, this enhancement of blue not happen, or happen at way lower rate.

 

[unthing]

Epic thread, great posts.

 

[knna]

SS, on the spanish group there is planned 2 hybrid HPS+LED grows. Unfortunatelly, they arenot started yet.

One is a 150W HPS, helped on top with Blue LEDs, and some red ones on the sides (to get an evenly light distribution on the x plane) and red and blue LED in side lighting configuration from lower areas. This setups has been working with the HPS alone, so we are going to check what the enhancement due the spectral suplementation and side lighting.

The other is currently a 2*1m (aprox 7*3') e&f table using 2 600W HPS, where one HPS is going to be replaced by 300w of LEDs (maximun power), with the target of at least keep production constant. The concept is exactly what you have explained you are planning, blue LEDs at the sides of the HPS and side lighting from the edges of the table. Another table in the same room will continue using the 2 HPSs with same strains, so its going to be an excelent side by side comparision.

 

[AllStar]

Thanks for the knowledge everyone. How many Cree's can i put on a 17w 700ma Xitanium driver?

 

[knna]

Thanks for the knowledge everyone. How many Cree's can i put on a 17w 700ma Xitanium driver?

Its able to give 24V (17W/0.7A). White (blues) draws about 3.5V@700mA, so it will run 6 of them and maybe 7.

Reds draws about 2.5V, so that Xitanium will run 9 reds, maybe 10 (depending of the forward voltage of the batch you get).

 

[AllStar]

thanks knna. sorry for the electrical questions but can i hook up cree xr-e neutral whites with golden dragons on the same driver?

 

[scroogemcgruff]

so what is the verdict here? i'm a new grower and i want to use the bestest most efficient light spectrum or whatever. i was thinking of investing in a LED GlowPanel for a micro closet operation.

 

[knna]

As far as the driver is a constant current one, yes, you can mix different models and color. The only requeriment is they work at the same current.

 

[DaVinci]

@ scroogemcgruff, LEDs are still pretty experimental, and this thread is trying to figure out the verdict you're looking for. If you really want to use LEDs, maybe try using HPS or CMH (whatever your preference is,) and add in some reds and blues. If you have the technical ability, make your own. Buying them is less cost effective right now. Unless you have the cash to shell out....



Wow, sorry to be gone so long, I was on "vacation." Truth is, I have suddenly found myself unemployed! Damn economy. Unless I get my job back any time soon, (unlikely in this climate,) I'm not gonna be getting that light I want this summer. I'm so pissed off. Right now, just trying not to let it get to me, and looking for a new job, if I can find one.

I hope I get one. I can't buy quality LED lamp components on unemployment wages.

So anyway, If I can't build a light, I can at least help out on the forums right? Any ideas of way I can help out knna? I need something to keep this stuff off my mind. Mindless work that anybody needs done? Crunching numbers, calculating spectrum outputs? Gimme some homework! (This is me trying to stay positive.)

 

[LeoRexTyrannus]

@Scrooger

Depending on your square footage you're going to want either multiple 400W CMH, perhaps a single 400W CMH or 250W version.

Check the CMH thread on this very forum it contains all the specific information I required to get a proper ballast, to purchase the bulb, orientation to your plants, etc. It truly is the most detailed source available on CMH in relation to Cannabis that exists at this time to my knowledge.

Now if you can't justify buying new magnetic core ballasts and you already have digital ones, then I would suggest as was suggested above that you go with HPS.

Basically if you don't have the equipment and its a new purchase get CMH if you have digital ballasts already, go HPS for convenience.

DO NOT BUY A GLOWPANEL, I had a GLOWPANEL 45, Weezard had one, they're cheaply built, overpriced pieces of Chinese crap.

With that in mind if you'd like to try CFL (T5 etc) or a hybrid grow just say something, I'm sure someone in here has solid ideas they can articulate for you.

@ General

I guess no one knows of a cheap timer that will fit my needs, :: sighs :: its been 6-7 days, and still no roots on my clones in the ultrasonic fogger, the clones that survived look very healthy but still no root mass from the stems. I cut back the fog from 15 minutes every hour to 15 minutes every 2 hours, hoping that helps, anyone with experience with this like KNNA please PLEASE give me some advice sirs!

 

[LeoRexTyrannus]

@Knna

I got my first roots on 2 of the clones! I believe my less aggressive timing of 15 minutes every 2 hours was the key, leading me to believe with ultrasonic fog that less is more.

Sorry for bothering you with this, its just you're the only guy I know in here that's messed with these.

 

[Weezard]

A'ight. Since you ask.

A'ight. Since you ask.

"PLEASE give me some advice sirs! "

You could be overthinking this.
Mo' betta, you apply some KISS.

You no gotta buss' you ass.
Clones'l root in a water glass.

Jus' 7 days? What's yer hurry?
Nudder 10, den you worry.

Seriously, you don't need to agonize about timers n times.
If you run the fogger 24/7 your gals will be just as happy.
Fog is ideal for rooting and you can't have too much.

The amount and quality of the light has more effect.
So does RH.

I've started pot cuttings by droppin' their stems in a glass of water.

Jus' can't let the water go "flat".
Either change out the water with fresh, aerated water twice a day, or poke 'em through the lid of a water pail with an airstone in it.

No rootone, no surgically sterile tools, no big deal.

Cuttings want to root and will do so under a wide range of conditions.
I've cut them with my dirty pocket knife and stuck them in pots of coco.
Worked very well when kept moist and shaded.



Aloha
Weeze

 

[Weezard]

@Knna

I got my first roots on 2 of the clones! I believe my less aggressive timing of 15 minutes every 2 hours was the key, leading me to believe with ultrasonic fog that less is more.

Huh?
That's kinda like the folks that get impatient with their bud size at week 5 or 6.
They run out and buy some "Superbudkaboom" for large $$.
Then when the buds do their normal 7 week plumping, they say "wow, dis stuff's da bomb!" and tell everybody how great it is.
Buds will swell around week 7 any damn way.

I would agree with your conclusion here if you had 2 foggers with 2 different time schemes and different results.
See what I mean?

Sorry for bothering you with this, its just you're the only guy I know in here that's messed with these.

Looks like I type too slow, yah?
We jumped posts.

Weeze

 

[LeoRexTyrannus]

Nah Weezard, I type too fast is more like it, Well I read over 30% oxygen is toxic, so I was thinking if the timing isn't proper or you do 24/7 it'll be overwhelming, I breathed some of the fog... it'll kill you, it's hyper moisturized, even with the oxygen in it its too moist to breath.

I think that's why that dude was saying he runs a cycle of 1 on 4 off and in summers 1 on 5 off to allow it time for oxygen.

I don't know but since I switch to 15 every 2 hours I have five clones with roots sprouted and the previous two I reported have gained drastic mass for such a small scale of time.

I think tomorrow I'll start a thread and take some pictures of what I'm talking about.

 

[unthing]

Hi Davinci

I was thinking that if you need something to figure out, why not come up with theoretical suggestion for a stealth grow box/cab/shelf in the spirit of this particular forum, passive cooling or something really quiet, Leds somewhat equivalent of those 100-150 watt multlight cfl-systems. Or a 100-150 w hps. Throw a veg and mother chamber there and cost too.