Astir Grow Led Panel Project...

Hi,everybody.

This is the last part of an experimental journal.
The first part was uploaded in a forum that no longer exists..
So ,'cause there wasn't any photo back-up ....Everything is gone...
Those of you who know about the journal,you may have the opportunity to find out ,how it finishes..

Tech info:

-1 female specimen of the hybrid " White Russian ".(From regular seed.)
-25 liter Black peat / perlite ( 60% : 40 % )

-Ferts used:
-Miller Nutrient express 18-18-18
-Miller Sugar Express 4-10-40
-Liquid MaxiCrop
-Yara Krista K plus ( KNO[SUB]3[/SUB] )
-Epsom ( MgSO[SUB]4[/SUB] )
-Fossilised Lithothamnium Calcareum +15% MgO

Also used:
-E 330 (Citric Acid ) as an pH / acidity regulator
- Polysorbate 20 (Tween 20 ) as a non-ionic surfactant agent ( wetting agent )

Water : Mix of really bad tap water & RO Water....

Click to expand...

Vegging: Terrible 4 weeks vegging with 96 Watts of really wrong led spectra of 6x cool whites,2x warm whites,4x reds 660 nm & 12x reds 630 nm ( 6C.2W.4R[SUB]660[/SUB].12R[SUB]630[/SUB] )...
Plant showed signs of excessive light irradiation.Full sun light adaptation.
Small & thick leaves.Small number.Dark green in appearance .(Lots of Ch A !...Not so good for a C3 plant ...)
........
Topped at 11th day ,to two main branches.Left to grow tree-style.
Finished vegging with a mere 15 cm of height and a very limited amount of leaves ( low photosynthetic active area ).
No signs of Shade Avoidance Syndrome...
Fair streching ,probably due to elevated temps ( 35° C ).
660nm reds ,are not appropriate for C3 plants.At least not without the same radiometric(power) amount of 720-740 nm light.

Beginning of flowering up to 35th day (end of 5th flowering week.):
Lights changed to 2 units ( 44 Watts total ) of 8C.12W.4R[SUB]630.[/SUB]..

Life came back to specimen.....
Flowering showed no signs of retardation .
It seems Warm White leds are far more efficient from monochromatic ( actinic ) red 630 nm or 660 nm.
Plant at day 35-today- has height of 70 cm...
Showed weird shinny ' slimmy ' spots on most of leaves...
Probably too much Tween 20 ( 200ppm / Week ) .Millers also contain surfactants.
Needs further investigation.

Flowering Day 35 : Today....
Changed number of units to three.
66 Watts in total. ( 3 x 22 Watt )
Units Spectral codes : 2 x 6C.2N.12W.4R[SUB]630[/SUB] & 1 x 8C.12W.4R[SUB]630 [/SUB]
5 weeks left,till harvest .....
From now on ,with 66 Watts of leds...


( Astir Led Units : Typical unit consists of a massive 20 cm x 16 cm x 5 cm 6061 Aluminium Alloy Heatsink with 16 cooling fins ,a 24 pcs led MCPCB,24 Asian leds 1 Watt chip Φ 8mm with no lenses .Asian Constant Current Driver. .Weight: 1990 grams .-Part of- Multiple Unit Surround Led Illumination Project. Experiment Group #1 .Typical Wattage : 20-22 Watt / panel.
Astir is a( soon-to-be.. ) small,european ,high-end but low price , growing equipment company.)

Noob question: what is a C3 plant? Why is 660nm bad for them?

Lovely looking plant.

high end but low price? since some manufacturers of panels are hitting the 2 dollar a watt mark pretty easy how much is this one costing per actual watt?

dbkick said:

high end but low price? since some manufacturers of panels are hitting the 2 dollar a watt mark pretty easy how much is this one costing per actual watt?

Click to expand...

About 50-55€ per unit ...
Aprox. 65-70 $ per unit (complete with driver,hanging chain & clips, plus one easy-roller...)
The main cost of this unit is the massive heatsink.Astir uses passive-cooling .(No fans,closed boxes,ect ) ..
Led efficiency -specially the reds -and usage life depends heavily on effective & trouble free cooling...
The leds,mcpcbs & drivers are cheap asian.Since they are parts subject to constant change and development.
Thus,they have to be economic ,for upgrading the unit(s)...
Still,they work fine....



Thing is that no 3-Watt chip leds are used,neither small heatsinks..
Also these units are not designed to work as a single point light.( zenital )
Each has its own 'sector' of canopy to illuminate.
So ,in fact ,one needs 9 to 12 units ,for illuminating effectively, one square meter of canopy.

price seems reasonable enough but hanging 12 lights doesn't sound like much fun.

C3, C4 plants
http://wc.pima.edu/~bfiero/tucsonecology/plants/plants_photosynthesis.htm

Yep...That's a bit troubly....
But it is worth it...
These are designed mainly for SOG /Scrog applications ...


Finally it seems tha the ratio Cool / Warm Light ,2 : 1 works fine...

Probably ,fine tuning ,the spectra to 4C.4N.12W.4R[SUB]630[/SUB] :
-4 x cool whites ( 6000-9000°K )
-4 x neutral whites ( 4500-6500°K )
-12 x Warm Whites ( 2500-3500°K )
-4 x Red 620-640 nm ( 630 nm )
,offers the best all-around solution,for both vegging and flowering...

Some notes from the research :
-The use of 660 nm reds are not only unnecessary but may prove catastrophic..
650-680 red,together with 720-740 nm far red (near infra red ) ,is provided by the warm white leds,in portions suitable enough for alternate Phytochrome state conversion,so
that both photomorphogenic and circadian cycle responses ,are close to optimal.Probably more than enough 660-730, Emerson Effect related light,is radiated from 12 pcs of Warm White leds.... Thus ,the streching during 3rd week of flowering and the fast -pace flowering rythm...

-Orange-red range ( 580-630 ) seems the most effective range for photosynthesis in C3 plant Cannabis Spp.

- Fair amount ( 20-30% ) of Green-Yellow ( 550-570 nm ) light is needed to provoke limited Shade Avoidance Syndrome (Large Leaf Lamina ,Extended Petiole ).
Thus maintaining older/lower fan leaves,photosynthetically active and giving them the ability to reach to a ideal size ,to serve as large nutrient resources ( Mobile elem. N,P,K,Mg and glucose/fructose /starch ),specially needed for the-demanding- late stages of flowering ...

There is a question. Is it necessary to prepare optimal light conditions for the photosynthesis of all leaves on the plant or not? What way is it determined? The correct decision on spectral composition of light depends very much on certain morphological characteristics of plants. There is a dependance upon the distribution of fruits along a stem (Tikhomirov, 1990). For example, cucumber has equal distribution of fruits along the stem. There every leaf supplies assimilate to its fruit. In this connection cucumber leaves at all layers must be provided with optimal light conditions. This requires a large portion of green rays in PAR (about 40%). Red rays in PAR (about 40%) provide high level of photosynthesis of upper leaves. Green rays penetrate into middle and lower leaves of plants. Blue rays have regulatory function, but its part in PAR is not very big (about 20%) (Tikhomirov, 1989).
.......
http://biology.mcgill.ca/Phytotron/LightWkshp1994/1.3 Tikhomirov/Tikhomirov text.htm

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-Cool/Neutral whites supply,the 20% of blue light ( 440-460 nm ) needed for photosynthesis ,photomorphogenesis,phototropism and anti-oxidants biosynthesis.
Also blue light ,generates heat,inside the plant.Both by mechanical/physical (Water molecule vibration ) and photochemical (blue photon energy drop ) reactions...

-Actinic leds (except of blue ) are not efficient(or stable at their efficiency ) as YAG phosphor leds.


-Pink phosphor leds ,should be taken under consideration for future use in growing spectras ,as they possess a well suited spectrum....



-Full spectrum White light it is still the best for growing purposes ...
There are still -probably-many ( photosynthetic or no ) photo-reacting plant mechanisms ,that we are unaware of their role..
Or even ,how exactly they work,at all...
...
So,a mixture of Cool,Neutral & Warm white leds ,with a photometric efficiency already at 130-140 lm / Watt ( average 2012 chinese cool white led ),is more than capable of successfully irradiating/illuminating -growing/flowering- plants in controlled enviroments....

-Use of low levels ( 0.5 Watt Φ / m[SUP]2[/SUP] ) 'oxidizing ' UV radiation (UVa at 360-370 nm , UVb at 280-310 nm ) and its role in anti-oxidant qualitative/quantitative terpene/cannabinoids biosynthesis ,(as a Stress Activated Response result ) is still something that needs further researching and experimenting..

Excellent work, I've been following the journal from the other forum and have been part to the led manufacturing. We have found a way to solve the problem of the panels moving up and down all together just yesterday. Here's the photo.



Obviously will be following the grow since I'm gonna start a similar one in the next few days. The photo I'm showing is from a mate's grow who's also trying out the same panels with different spectrum.

Judging by your plant I'd say you'll definitely hit the 1g/w mark, I'm thinking at 1.5g/w

I think ,with your friends',current set up ,too much light is wasted...
He should gather the plants and the units as close,as possible......
Instead of having 6 units in line ,he should try having them as a " square" over the plants....

On the other side of the room there are two more plants getting light from a 400w MH/HPS. He's making a test grow to see if the lights worth their money. 5 plants with a common reservoir. I'm gonna start a similar grow that'll be 5 clones from the same plant all under different spectrum in separate boxes. It'll be a funny autumn

Yes,indeed,my brother !

Oh boy! I love experiments..
And this project seems promising.
Very nice plant for so low power cons..

I am thinking of a 80x80 box with 4 led panels such as those and one or two plants (scrog probably).
Temps are ok without fans on the panel? Wouldnt be better if it had a couple of pc fans instead of the aluminum?

[following topic]

led is always interesting.. nice going grow!

subbed!

Good luck mister!

Panas1 said:

Oh boy! I love experiments..
And this project seems promising.
Very nice plant for so low power cons..

I am thinking of a 80x80 box with 4 led panels such as those and one or two plants (scrog probably).
Temps are ok without fans on the panel? Wouldnt be better if it had a couple of pc fans instead of the aluminum?

[following topic]

Click to expand...

No...The heatsink is massive enough ,to keep the leds running really cool...
With ambient temp of 34°C ,the heatsink had a temp of 38° C on its fin base...( cycle 24/0 !! )
Also the front side of the MCPCB was at 38-37° C ,also...
It runs pretty cool...
No need for fan...

Question: The size of the panels is fixed or it can be adjusted on tent/room size ? I mean, if i have a 80x90 roof space ,can i just put one panel with these dimensions or it has to be several panels to fill the mentioned roof space?

agios said:

Question: The size of the panels is fixed or it can be adjusted on tent/room size ? I mean, if i have a 80x90 roof space ,can i just put one panel with these dimensions or it has to be several panels to fill the mentioned roof space?

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Well,it depends on tent/room size ,also....
For that area (80 cm x 90 cm =0.72 m[SUP]2[/SUP] ),9 panels should be adequate...

These panels perform at their best ,on ' screened ' plants ( like SCROG ),due to lack of extra lenses..
(Cheap polymer [Polymethyl MethaAcrylate -PMMA] lenses,have more than 15% light power losses ,due to absorbance .
Also ,for the spectra to ' mix ' well enough - narrow light emission angle of lenses- one needs to increase the distance from canopy.More light power losses,due to reverse square distance Law..Those are the main reasons for,lenses are not used...)

Each panel can effectively illuminate an area of 30 cm x 40 cm ( .12 m[SUP]2[/SUP] ),with an effective ' penetration ' depth of 30-50 cm,depending of the canopy density/quality.Ideally with an average performance of 1 gr/Watt ,9 panels should harvest,at least 198 grams....( Aprox. 7 ounces).


The main purpose here,is to get the same ' average ' gr/Watts as with Hid illumination ,but using half the power ( Watts ) and even less total energy( gr / kWh ),as one can utilise them gradually... (from 1 panel the first vegging week ,up to the max number, during mid & late flowering..)

Also growing with leds ,has nothing to do with " horsepower" as with zenital single-point lighting..
Leds emit multiple light ' cones' ,as opposed to the 'sphere' of light ,conventional light sources,emit...
Moreover,in the case of leds,one must take full advantage ,of the ' surround ' lighting ,they offer ..(Nasa refers to ,as ' intracanopy ' illumination )..
That translates into,more than one 'powerful' panel....
Instead of that ,multiple,smaller power panels are utilised...
'Dividing' or 'disturbuting' the precious light power ,more evenly(and effectively ) to leaf canopy,leads to bigger yields...
Also leaf bleaching ,due to high radiation levels is,easily,avoided...

Everything is a compromise, isn't it.
IMHO, what we are after with leds, is the maximum number of photons for a given wattage. Unfortunately, watts translate into heat much better than photons as shown in the use of HIDs'.
Here is a little paper that addresses that issue with leds. http://ledsmagazine.com/features/9/9/5
When we feed a watt to a led, that watt is going to be dissipated either as light or heat, we want light of course.

The NW leds are indeed in the "Goldilocks zone" and I think that we are on the correct path here, though I think using high quality name brand top bin leds of greater power should yield better results.
Think photon density. All things being relative, it still remains to be seen at what size and power densities leds will be most efficient at producing light.
Also we have not taken into account what effect the wave and quantum properties of light have on morphology.

It looks like you have a major winner here. Good work!

Seems like a good job, good luck with it.
The major advantage theese panels have, i think is that you pay much for the heatsinks, but theese are for ever.
That means that you can upgrade the leds at any time with new more efficient leds with low cost.

tenthirty said:

I think using high quality name brand top bin leds of greater power should yield better results.!

Click to expand...

Indeed, but since the led lightning is new technology, every year the lumens/watt ratio will rise fast.
So since in 2 years there will be the possibility to upgrade the leds to more efficient ones, buying now top-brand and expensive leds is a waste of money

tenthirty said:

Everything is a compromise, isn't it.
IMHO, what we are after with leds, is the maximum number of photons for a given wattage. Unfortunately, watts translate into heat much better than photons as shown in the use of HIDs'.
Here is a little paper that addresses that issue with leds. http://ledsmagazine.com/features/9/9/5
When we feed a watt to a led, that watt is going to be dissipated either as light or heat, we want light of course.

The NW leds are indeed in the "Goldilocks zone" and I think that we are on the correct path here, though I think using high quality name brand top bin leds of greater power should yield better results.
Think photon density. All things being relative, it still remains to be seen at what size and power densities leds will be most efficient at producing light.
Also we have not taken into account what effect the wave and quantum properties of light have on morphology.

It looks like you have a major winner here. Good work!

Click to expand...

Well..
Some points worth of consideration....
"....the maximum number of photons for a given wattage..."
Or in other words μmol/sec (Photosynthetic Photon Flux =Joule/sec=Watts )..

Hmm...Let's wonder :

-Do 100 μmol/sec of green light ,have the same photosynthetic efficiency (measured in O[SUB]2[/SUB] evolved ) as 100 μmol/sec of red light ?
Obviously ,no..

-Is the red 660 nm (more photons per Watt ) more efficient in photosynthesis ,than 630 nm red ?
No,at least not for the C3 plants..(Which have lower ChA/ChB ratios than C4 plants )

-Are ,the known action & absorbance spectums ,up till now,of photoreceptors like ChA,ChB,xanthophylls(Zeaxanthin,Carotenoids),Anthocyanins,ect ,correct or at least accurate ?
No.Action & absorbance spectrums of photosynthetic main & accessory pigments,are calculated ,while in form of dilutions (in-vitro,with organic dilutants/solvents used ).
Organic solvents used,deviate enough,the action & absorbance spectrum values, of the photoreceptor pigments,from their in-vivo actual values..So ,they're just ,'indicative' general values...Nothing more...

-Also ,one should take into account,the lower the photon energy (towards the red end of the visible/PAR spectrum ),the more prone these photons to be
absorbed by water.(Inside the cell tissue)..

So ...
It's not just the μmol/sec (or mole/day if you prefer ..),only...
One should take into consideration,the Relative Quantum Photosynthetic Efficiency ,per nanometer of wavelength..
It seems so far ,C3 plants ,really 'like' (have evolved to use more efficiently ) the orange-red part of Par range(580-630 nm )...

Also..

Since green light,which is mainly reflected or transmitted through leaves,is considered to have a "low photosynthetic efficiency " ,but still
plays a major role in photomorphogenesis (Shade Avoidance Syndrome ,often together with far infra red -heat-...),it is absolutely logical to imagine
that blue & red light alone ,aren't enough for normal plant growth and development.Because we do not know much about the role of other wavelengths,it does not mean that they are useless or a waste of energy,as mistakenly is,often, being thought and 'understood'....
................................................................................................................................................................................
Neutral White leds ,provide enough light in the blue and green/yellow area of PAR...
Alone ,they are not sufficient for illuminating plants at their full potential...
Plants still need orange,red,far red ,ect..
...............................................................................................................................................................................
"...though I think using high quality name brand top bin leds of greater power should yield better results...."

Yes,of course..A pretty small difference...No way close, to the 10x difference of their price ,compared to cheapo asian leds....
Plus,the fact that leds develop and evolve ,almost every year...
It's bad idea to pay a good amount of money ,for leds ,that next year are 'old history'....
Cheap leds ,are easy to change/service and upgrade.....
The lack of binning has a ..weird good side.....Diversity..Small variations to fill the 'gaps'....And that is a good thing ,at least with spectra...
And...As you can see ..Cheapo leds (130-140lm/Watt ) work just fine....
Next year's cheapo leds ,will be even better....
Why pay a small fortune for high-quality 'yesterday's news' ?
Better pay for a top grade heatsink...(That will never has to be changed/serviced/upgraded....)
....................................................................................................................................

Photomorphogenic responses do not occur only based on power(quantity) or spectra(quality) of light...
They are,far more complex mechanisms affected,also, by time length(duration) of irradiation and angle / direction of light ....
...........................................................................................................

Re-discovering the white light ?