7 plants under 400W ASTIR LEDs in Hydro-Aero System

djwimbo

djwimbo

Well-Known Member
Scotch089 said:
I had a custom ratio made up with them of WW and R's, they dont have anything over their 630... :(

Think it was 18:6..?

EDIT Sorry, 16:8

I will say they were unbelievably helpful, redrew my diagram of the 16:8 for a better, more even spread. They were honest about shipping, and very down to earth, straight forward people.

I feel rather guilty not investing yet, but my time in this hobby may be running short..
Click to expand...
Bummer, that changes a couple things. I might have been a critic of the company before, but I'm learning and now I want to buy their stuff.
 
PetFlora

PetFlora

Well-Known Member
Thanks Bluez,

I'm thinking 3-2-1 also. I guess it depends on whether the WW covers any 640. So one might only need 650+660 (~8:1?)
 
Bluezdude

Bluezdude

Well-Known Member
PetFlora said:
Thanks Bluez,

I'm thinking 3-2-1 also. I guess it depends on whether the WW covers any 640. So one might only need 650+660 (~8:1?)
Click to expand...
As I said, can't really tell, just speculate. I think that is like a quest for the holy grail, the perfect spectrum!
 
ganja 2

ganja 2

Active Member
50 litres fresh water

Grow 5ml/10lt
Micro 10ml/10lt
Bloom 16ml/10lt
Bud Candy 2ml/10lt
e.c. 2,5 - 2,7
100_3544.jpg100_3538.jpg100_3539.jpg100_3540.jpg100_3541.jpg100_3552.jpg100_3547.jpg100_3549.jpg100_3542.jpg
 
stardustsailor

stardustsailor

Well-Known Member
Great Job ,brother ....

Well ..Come to think about it ,once more,seeing the pics ....
Mosaic(type of ) Viruses ,are becoming the worst enemies, regarding led growing...
(Due to lack of emitted "deep IR" radiation -aka heat ? ... )..

 
PetFlora

PetFlora

Well-Known Member
Found this on another site. It's over my head, What do you guys think?

I was just working on sourcing a driver that will do a 720hz frequency and 50% duty cycle and I started thinking about your kill-a-watt results... they could vary widely based on the light being constantly driven or on a lighter duty...

People are currently marketing constantly driven LED arrays as "grow lights" assuming that the plant will have access to more light which will make it grow more or faster or whatever.

While it is true the lamp will deliver more light to the plant, is the plant actually using any or all of it??


Abstract.
Effects of intermittent light on photomixotrophic growth of potato plantlets
in vitro and the electrical savings that could be realized by adjusting the frequency and
duty ratio of light-emitting diodes (LEDs) were investigated and compared to the use of
conventional tubular fluorescent lamps (TFLs). TFLs provide continuous fluctuating light

at 60 Hz and LEDs provide continuous non fluctuating or intermittent/pulse light depend

on the preset frequency and duty ratio. In total, eight treatments were investigated with
varying light source, frequency, duty ratio and photoperiod. Results indicated that if
growth rate is the only concern, LEDs at 720 Hz [1.4 milliseconds (ms)] and 50% duty
ratio with 16-h light/8-h dark photoperiod stimulated plant growth the most. However,
if energy consumption is the major concern, using LEDs at 180 Hz (5.5 ms) and 50%
duty ratio with 16-h light/8-h dark photoperiod would be the best choice for illuminating
potato plantlets without significantly sacrificing plant growth, especially when energy for

heat removal is also considered.


http://hortsci.ashspublications.org/...2/375.full.pdf
http://www.geocities.ws/sash_elias/files/thesis1.pdf


When a plant cell receives a photon, it begins a whole cascade of events. The cell is not ready to receive a new photon until a good portion of that work is done (something like half way through from what I understand). Based on the results from what I linked, 720hz @ 50% duty is fast enough that the plant does not ever wait to receive a new photon. They showed that as low as 180hz @ 50% duty is still fine for the plant... at this frequency it is favoring the electrical cost side, at 720 it favors the plant growth.

From the testing that I linked, they were able to go as low as 180hz before it started to effect plant growth. So I agree with you that there could be different speeds of cellular action, but also there should be a maximum that feeds all actions and still has electrical savings. Just like how our eyes accept anything over 60hz as constant light.
 
stardustsailor

stardustsailor

Well-Known Member
Well ...
Have given some thought on that issue already ,not so long ago ....

In fact ,"pulsed operation " ,has a lot to offer ....

-Increased service life of leds
-Less cooling issues or more light power (more than of max .current ,at continuous operation )
-Economy


But ....
720Hz 50% d.c. , 16/8 ,for potatoes works ....For mj ?

..
Frequency ,has to be a "harmonic " of ~4 Hz ..

http://kirschner.med.harvard.edu/files/bionumbers/confBioNumbershandoutphotosynthesis.pdf
Maximal absorption rate under full sun illumination of chlorophyll pigment: ~ 4 sec-1
Click to expand...
So for potatoes 180x times the max. absorption rate ,is enough .....
( 180 x 4 = 720 )


-And that is for Chlorophyll molecule only ....

-What about the rest of photo-arresting /harvesting pigments/protein complexes ?

Each chloroplast absorbs photons at different point ,than other chloroplasts ....

So ...There's a random "phase difference" ,between all chloroplasts ...

Potatoes need 180 different "phase outs " to be "covered " ,in terms of photon absorption ...

Each chloroplast can harvest photons 4x times per sec ....

Supplying photons 720x times per sec ,
then 180 differently" tuned " operation bands of chloroplasts,
can be "fed " with constant supply of photons .....
(at each operation 'band' ,chloroplasts are "tuned " to absrorb photons simultaneously .. )

-How many "bands" "fed " ,does mj need ?


Yeah ....
Right ....

...

-What about reflected light ?
( Greenhouse vs Growroom ,differences again ....)

A bunch of photons that went " from Rome to New York ,through Cape Town "....

" Out of phase ,reflected light " ..
..
Hmm....

I'm guessing ....

For now ...
For me...
Continuous operation of leds ,will do just fine ..
 
heckler73

heckler73

Well-Known Member
50% Duty cycle means the power is being pulsed. So for half of the cycle, it is FULL ON, and for half it is off.

The first study is suggesting that 720Hz@50% LED is a better performer than steady state LED light.
THAT is interesting. Afterall, what is the minimum time for the photosynthetic process to occur? And at the same time, why doesn't steady state provide optimal growth (saturation?)

EDIT: I see SDS just answered that question :)

One thing I dislike, though, is the shitty peer-review of that study... the errors on Table 1 are OBVIOUS and left uncorrected.
As well, the statistical errors show there may be no difference between the 180Hz and 720Hz cycles (the lower bound of the 720Hz and upper bound of the 180Hz treatments overlap).
So I wouldn't take TOO MUCH away from this study as hard proof, but it is still worth further investigation. (and I should do some more reading ;) )
 
stardustsailor

stardustsailor

Well-Known Member
https://en.wikipedia.org/wiki/Duty_cycle


720Hz 50% Duty cycle ,simply put, means that the led will switch on & off ,720x times per sec ... ( Duty Cycle = ~ 1.4 msec )
For ~0.7 msec will stay lit ,for next ~0.7 msec will stay off ..that thing 720x times per second ....

The driving current (example ) can be at 350 mA ,at 700 mA ,
at 1000mA (max at continuous operation) or at 1500mA or even at 2000mA ..
Depends on Frequency & duty cycle selected ...( And type/brand of led ,of course ... )
So Output Power can be increased .....


(Not to be confused with Energy*..Energy =Power x time ...
50% duty cycle is half the time ,of continuous operation ...

So if energy was 500mW(<=output power of led ) x 16 hours continuously (per day ) =28.8 KJoule ..
(energy given to plants ,per day ,by led emitter )
...
At Pulsed operation (50% duty cycle) with same led output power ,is half energy "fed " to plants ,in terms of Quanta (photons ) ......

For supplying the same energy as with continuous operation ,output power has to be increased to "compensate " ..
Or might it be a fact ,that this is really "wasted " energy ?

 
PetFlora

PetFlora

Well-Known Member
I still think my idea of a tunable crystal oscillator to achieve most harmonious freq range for LEDs has merit. Should also be useful for growing any indoor plants, as long as the tunable freq range is broad enough
 
stardustsailor

stardustsailor

Well-Known Member
From the other hand ,I say for miself :
"Stay away ,from there ,that you do not have any particular knowledge or business ,with ..."

Neither pulsed led operation or crystal usage ,up till now have shown any solid proof ,
towards " gaining " something regarding plant growth .....

They are nice "issues " though ,to "play around with "...
Who knows ?
Maybe ,indeed ,something of "value" is hidden ,somewhere there ...

But .....

Time ...

For me ,it already way ' restricted ' towards other, more important issues ...
I'd rather find the "food -cooked-& served -ready" ,regading theories/ideas , like those ...
IYKWIM ....

No time for experimenting ,further,with such things .....
(Not at the moment,at least .....)
 
heckler73

heckler73

Well-Known Member
PetFlora said:
I still think my idea of a tunable crystal oscillator to achieve most harmonious freq range for LEDs has merit. Should also be useful for growing any indoor plants, as long as the tunable freq range is broad enough
Click to expand...
Sure, it has merit... but at what cost? And tunable crystals? We use LRC circuits and PWM in the 21st century... crystals are from the 1950s ;)

To be frank, I have to agree with SDS on this; steady-state is good enough for me.
Besides, as mentioned, this study was for potatoes. We are (for the most part) interested in CHEMICAL production, not just biomass. So how will pulsing alter that?

For now, I feel it is more important to fine-tune spectrums before mucking around with hyper-efficiency power equations.
But definitely, down the road, this will become more useful (especially for commercial greenhouses where 50kW is considered small-potatoes ... oh yes, pun intended!)
 
stardustsailor

stardustsailor

Well-Known Member
heckler73 said:
Sure, it has merit... but at what cost? And tunable crystals? We use LRC circuits and PWM in the 21st century... crystals are from the 1950s ;)

To be frank, I have to agree with SDS on this; steady-state is good enough for me.
Besides, as mentioned, this study was for potatoes. We are (for the most part) interested in CHEMICAL production, not just biomass. So how will pulsing alter that?

For now, I feel it is more important to fine-tune spectrums before mucking around with hyper-efficiency power equations.
But definitely, down the road, this will become more useful (especially for commercial greenhouses where 50kW is considered small-potatoes ... oh yes, pun intended!)
Click to expand...
.......
Exactly!
 
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