Another DIY LED experiment.

Sluggy

Sluggy

Okay, I made a few more mini LED panels. All components come from Ebay. This is cheapo stuff from China (more money for beer). 

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Okay it doesn't look very professional or anything, but YAY it works !  The LEDs are randomly equipped with 30,60 and 120 degree lenses, and Holy Laserbeam Batman, this light is INSANELY bright.  

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So I conjured up about 5 or 6 of these 30 watt mini-panels, which I call "modules".
Here' a few "modules" in my grow closet which is one square meter, say 3 x 3 square ft. 

200 watts should probably do the trick for a small grow space like that. 


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Now most indoor growers with comparable small spaces will typically use one single light source, say, a 250 watt LED panel or something. 

The plants will always get light from the exact same stationary source. From the same angle. And that light will always be in the exact same wavelengths or spectra. 

My idea is to experiment with 7 or 8 of these mini "modules"  of 30 watts each, which all have varying color LEDs,  and then put timers on them, so only 5 will be on simultaneously at any given time. 

F.e.

Module 1 will be on from 8 am til 6 pm
Module 2 will turn on at 10 til 6 pm
Module 3 from 10 til 8 pm 
Module 4 gives an extra blast from noon til 4 pm.

etc. 

This way, the peps get different, varying colors light from different angles all the time. 

I wonder if this will "stimulate" the plants. 

Now this may sound like a far-fetched idea but I like to experiment with this kind of stuff. 

It might just work :) 
















 
 
I love this. Especially the varying light-spectrum cycles. If you poke around, there is some great information on mimicking the natural variance of the sun, if you're interested.
 
sp33d said:
Sweet man....how much was total cost?
Click to expand...
I was trying to not sink a whole pile of moolah into these experiments at once. 
So every month I bought some odds bits and ends from Ebay. Maybe 30 bucks a month, if that.

The 660 nm LED diodes are a bit more pricey than the 630nm ones, Maybe a buck a piece vs pennies. 
You will need a constant current power driver. I got some 330 mA ones (which doesn't drive the 1w LEDs at full power), which can supply current for 24 to 30 1w LEDs.  These typically cost $ 12 - 14 US, postpaid. 

This is where those PCB's (circuit boards) come in.  The round ones are for 12 diodes, the rectangular ones for 18. Makes 30. So that works out nicely. 
Thermal glue is a bit (a lot actually) costlier here, after a while I ended up buying from Singapore 90 cents a (mini) tube.  Postage paid. 

Heat sinks are partly purchased from Ebay (4, 5 bucks) or DIY using aluminum "profiles". 



Another incentive for the "modular" approach is that if one module fries, I can easily replace it, or keep growing. 
As opposed to a full 250 watt panel being temporarily unusable because one LED burnt out.  

Altogether I estimate the expenses at maybe 120 euros or so, (180 USD) but that's just a shot in the dark. 








 

miguelovic said:
I love this. Especially the varying light-spectrum cycles. If you poke around, there is some great information on mimicking the natural variance of the sun, if you're interested.
Click to expand...
I was also interested in this subject, actually :)
Theoretically you could mimick sundawn til sunset in your growspace, I suppose. 

 

 
 
Research from awhile ago, but I believe the jist is -
 
Infrared Dawn shifts toward Mid daylight (Complete white/blue heavy), then to infrared Dusk, overnight mild UV-lighting to simulate the Moon.
 
I may be wrong. It was an interesting theory for more natural indoor plant growth environments we were throwing around one afternoon over a few spliffs. LED spurred the discussion, as you can't really get the same ease of control with HID lighting, without using some sort of multi-bulb system.
 
The time of year is important as well. Variances in light spectrum and intensity are the on/off switches in a plants circadian clock. This may be a component in why it is difficult to grow long flowering sativa from raw seed naturalized to different areas of the earth, in a standard 12/12 red dominant light cycle.
 
The incomplete spectrum so often used indoors, by cannabis growers especially, produces physically weak plants highly susceptible to pest and disease, mainly through the lack of UV radiation.
 
 
Well that was a fun ramble to stretch a weak brain muscle. Some of it totally irrelevant XD
 
You could simply add a special UV-bulb from a reptile/pet store, or chuck some UV LED's in the mix of your LED setup. 

A lot of this grow info comes from online 420 grow communities, and while that kind of stuff is practically science overhere (Amsterdam), the catch is that what works for cannabis doesn't neccessairily have to hold true for chilli plants. Them is two different critters imho. 

For instance : 

A chilli plant doesn't have defined or distinct seperate veg and flower phases. You also can't force a chilli plant to start flowering by reducing the light from 18 to 12 hours a day.  And if you take a clone from a marijuana plant it's basically a seedling. But my findings are that chilli clones are NOT : Once a pepper clone established some kind of root system it's not like a seedling or baby plant, but a mini plant that is in the same phase as the motherplant. 

So those are some differences right there. 

While the "cool white/blue for vegging, red light for flowering" dogma might work fine for weed growers, I am not so sure whether it is the exact same for capsicum plants. I've grown a shit ton of seedlings under basic, cheap, run of the mill fluoro tubes. And to my surprise, these tubes initially outperformed my DIY "especially designed for seedlings" panels with blue, UV, royal blue, 5000 K, 6500 K, 10,000 K, 20,000K. Like, completely. 

This was surprising because theoretically the LED panel had the "perfect light" for seedlings. Except it didn't. 
Once I put those young plants under other LED panels with more red, they grew way bigger, stronger and more vigorous than their cousins under similar wattage worth of cheap fluoro tubes.

This seems to indicate that chilli seedlings DO need light in the red spectrum to grow, and that LED, watt for watt, is more effective (at least more effective than 2 year old cheap neon tubes).
 
 
Sluggy said:
You could simply add a special UV-bulb from a reptile/pet store, or chuck some UV LED's in the mix of your LED setup. 

A lot of this grow info comes from online 420 grow communities, and while that kind of stuff is practically science overhere (Amsterdam), the catch is that what works for cannabis doesn't neccessairily have to hold true for chilli plants. Them is two different critters imho. 

For instance : 

A chilli plant doesn't have defined or distinct seperate veg and flower phases. You also can't force a chilli plant to start flowering by reducing the light from 18 to 12 hours a day.  And if you take a clone from a marijuana plant it's basically a seedling. But my findings are that chilli clones are NOT : Once a pepper clone established some kind of root system it's not like a seedling or baby plant, but a mini plant that is in the same phase as the motherplant. 

So those are some differences right there. 

While the "cool white/blue for vegging, red light for flowering" dogma might work fine for weed growers, I am not so sure whether it is the exact same for capsicum plants. I've grown a shit ton of seedlings under basic, cheap, run of the mill fluoro tubes. And to my surprise, these tubes initially outperformed my DIY "especially designed for seedlings" panels with blue, UV, royal blue, 5000 K, 6500 K, 10,000 K, 20,000K. Like, completely. 

This was surprising because theoretically the LED panel had the "perfect light" for seedlings. Except it didn't. 
Once I put those young plants under other LED panels with more red, they grew way bigger, stronger and more vigorous than their cousins under similar wattage worth of cheap fluoro tubes.

This seems to indicate that chilli seedlings DO need light in the red spectrum to grow, and that LED, watt for watt, is more effective (at least more effective than 2 year old cheap neon tubes).
 
Click to expand...
 
I was refering in most part to cannabis growing :P and am aware of many of the differences you posted, though I appreciate reinforcement in my understanding by those that are knowledgeable.
 
Point of odour, I don't actually believe the red/blue dogma, and tend to fall in line with growers replicating a more complete spectrum. (Broad may be a better term, see below). Your findings growing under your initial DIY lighting are interesting. I would expect a heavy blue panel to produce a shorter, denser plant. What was the actual configuration and ratio for the original and the adaption?
 
The cheap fluorescent was a "warm" light?
 
Repost from another thread.
 
Anatomical features of pepper plants (Capsicum annuum L.) grown under red light-emitting diodes supplemented with blue or far-red light.
 
I assume the "broad-spectrum MH" to be a ceramic metal halide, which, ignoring the predominant green (standard pot grower paradigm XD), produces high amounts of red light, but with strong blue, UV and infrared. Different/newer CMH bulbs produce slightly different spectrum though, it would be nice to know specifically what they used.
 
Spectrums of three common CMH
 
I agree with you.  Although MH bulbs pump out a ton of blue, there are still sufficient other wavelengths for vigorous growth. 

A basic red/blue only combo doesn't seem to really to the trick. I've read people are having succes with white/red leds only grows.
 
That's an interesting experiment Sluggy - are you planning to use this for seedlings, or to grow plants to maturity?
 
I found this study that may interest you (click the link below to read the whole article).  The part that I found most surprising is that, for pepper seedlings grown for 21 days under monochromatic LEDs (i.e. red only, blue only and green only), "pepper developed normally under all three monochromatic LED treatments".  This seems to indicate that (for pepper seedlings) color does not make a lot of difference.  It would have been interesting to see how the plants would have continued to develop after more 21 days in these conditions, as color clearly made a difference to lettuce and radish (blue > red > green).  I suspect for long term growth, full-spectrum would be the way to go.
 
Kevin R. Cope
Mentor: Bruce Bugbee
[SIZE=small]On the importance of green light for plant growth and development[/SIZE]
[SIZE=larger]Link to PDF[/SIZE] 
Green light is largely reflected or transmitted by plant leaves and is commonly thought to have relatively small effects on both photosynthesis and photomorphogenesis. However, previous studies with whole plants have indicated that broad spectrum light increases growth compared to solely red and blue light. These whole-plant results are consistent with studies on single leafs. Unfortunately, the effects of green light are not consistent among studies. Although blue light is less photosynthetically efficient than red, it is vital for normal development of most plants. Green light is likely not as vital to plant development, but it is perhaps important for maximizing plant growth. Here we report the results of studies designed to evaluate the value of green light. We grew lettuce, radish, and pepper plants under eight LED treatments at photosynthetic photon fluxes (PPFs) of 200 and 500 μmol m-2 s-1. Our results indicate that green light is of little value during early growth stages when plants contain no overlapping leaf layers. However, because green light effectively transmits through leaves, it can be used to increase whole plant photosynthetic rates. Because of this, the value of green light significantly increased as plants formed multiple overlapping leaf layers. Additional studies are needed to confirm these results.
 
Interesting article, thanks. 

As far as I know and understand it, the observed effects from monochromatic light can only partly be attributed to the light color.  The tiny seed packs quite a bit of "growing power", but eventually all the seedlings will run out of steam if they don't get other wavelengths of light as well. Some will grow lanky reaching for light, others refuse to grow altogether or display other abnormal growth and development. 

So using multiple bands of LED light is really the way to go in long term grows (beyond seedling stage). 
So go with white LEDS which contain all colors. I'm not sure about the ratio yet. 

As far as my own experiments go, I plan to have about half a dozen DIY mini LED panels that switch on and off on different time intervals, so that the light sources "move" over the day, 
The plants grow towards the light. In the morning the light comes mostly from the left, in the afternoon from the top, and during the evening it comes from the right. 

I was wondering whether this "moving light" would stimulate the plants and make them stronger ?
Sure, it might just be a crazy idea, but who knows ? 

I saw an article on some cannabis website where they had single HUGE marijuana plant placed in the center of some cylindrical, revolving contraption with lights (alternating HPS and MH), not unlike a merry go round. It was like an industrial turbine almost ! 
That experiment was a succes. The plant was ENORMOUS. Like a christmas tree. 

I don't want to go that far,and I'm not a stoner, but still my experiment might yield interesting results. Who knows ? 

On a different note, the plants that are under the panels now, have definitely started to flower.
They said it couldn't be done with LED. 
Although the process that initiates the flowering may have been underway before I placed the plants in my grow closet, I'm inclined to believe for now, that the 660nm red LEDS really do stimulate budding and flowering. 






 
 
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