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DIY LED Full Spectrum Design

kingdamm

kingdamm

Seedling
Joined
1 Mar 2013
Messages
20
Location
Trivandrum, India
Hi Folks,
I designed an Led prototype for my 120cm Planted Aquarium,went through most of the topics posted over here on DIY LED and info was great.

Here are my Specification & Design currently in use
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1.Length of the Heat Sink Fixture = 110cm
2.Width of the Heat Sink Fixture = 12cm
3.Led Make = 1w Edison
4.Colour Temperature = 6700k
5.Lumen = 129.35 Lu /1w Led
6.Led in Heat Sink Fixture = 96 Nos ( 32w X 3 line strips )
7.Total Output of the Led Unit = 96 Watts

Attaching the vector image of my Fixture


hBZ4OpY.jpg


I would like to redesign my fixture with full spectrum Leds (RGB) to enhance better coloration,compact growth along with a tweak in their Photosynthetic activity.

Adding of RGB leds to my existing fixture replacing some of my existing 6700k.

1.Green/Cyan 525nm
2.Red 625nm
3.Royal Blue 450nm
4.Purple 410nm
Experts guide me how many RGB Leds should i require & where to position them.

Regarding T5 light systems and their spectrum's lot info's are available,but with regard to LEDs less info's are shared.Would like the experts come in and guide.Thank you in Advance..
 
Wow awesome beginning of project mate. Couple of things i have to mention here...
- are you sure the heatsink will handle so dense population of LEDs? any calculations? Usually the heatsinks are rated by heat dissapation and LEDs by heat irradiation
- having colour LEDs is a great idea and you will see how your plants respond like MAD, I dont really know why you need Cyan/Green as the plant leaves reflect green colour, as the human eyes are adjusted to green spectrum the most....so depending of yor White/green/red/blue balance, your tank might appear a bit greenish;) The only reason to put green Led might be that you like green plants to look greener but bare in mind that green spestrum is used by som sort of algaes as well
- if you see the photosynthetic curve will see the two peaks on deep red and royal blue, there is also gap on deep purple which you can cover with purple LEDs...I foun that as a waste of power as blue+red=purple
psnpigmentspec.gif
actabs.gif

- Colour balance?????? it is difficult to say really...as some people like reddish tanks and plants some swear that marine lights (white-blue spectrum) grow their plants like crazy and they are both right
I will recommend 60% 6500K, 20% Royal Blue, 20% Deep Red if you want cyan, gree, purple you have to trial and error the things:banghead: I have done for 30l tank 16 white XB-D Crees, 4 Royal , 4 Red Osram Oslons and gave me neutral ...not reddish or bluish colour and goor colour render at the same time. That is just from my experience with LED building
- LEDs spread on the heatsink??????? is another difficult task......What I have done is, considering how high will hang your LED fixture, what is your LED lightspread angle and the height of you tank, I imagined that every LED spreading light as a CONE, so if lets say the bases of two cones are overlapping at some point will get good light spread ...no blind spots and light spots.
Here is a rough schematic image of what I mean....excuse my drawing skills:D
Untitled.png

The bigger is your Led beam angle lets say 120 degrees, the more distance between the leds, the less number of leds due to the distance, the closer to the water level your fixture could be, the better overlapping between the ligt spredcones will be but the shallow water penetration of light will be.
And the smaller your Led beam angle will be, the less mounting distance between the leds, the more leds due to the distance, the higher over the tank you light could be, the better water penetration of light will be, the poorer overlapping of the light cones or more difficult will be.

So designing a good DIY led fixture fo a good price dependson:
-What tank will be illuminated the dimentions of the tank
- what will grow in the tank or will be just fish display tank or black water biotope lets say:rolleyes:
- how much can spend on light...you fixture has to cost less than ADA Aquasky Hahahaha:arghh:
and has to perform better than anything on the market cause all LEDs developers missing something or their Lights are too universal...and you are designing LED for specific tank which gives you advantage
- Put some Science in the whole thing and will be amazed from the results
- buy your LEDs smart regarding cost brand name, wattage, light spread angle, heat dissapation....just to mention I have got the new Cree XB-D silicone carbide technology and they are awesome regarding lumens per watt ang light spread, heat irradiation etc. they are really effective of what they do, but poor CRI (colour rendering index) the whole tank appear green/yellowish) so have to put some colours later on:oops:
- design yor led fixture regarding how high will be over the tank so no light waste on the walls or room around... it all depends again in the beam spread angle and led population on the heatsink.
-make an Alfa prototype when trial and error the things and then upgrade it untill you are happy with the results

I wish you LUCK from all my heart:)
 
Hi very good topic!
I made my DIY led fixture also. 80% happy with results.
Clone made very whise advises. I agree that you can have a big advantage to design your own light.
My aproach lies on the side of thinking about specific plants.
Why have all tank light equal?
I dream with a fixture that mange specific plants in specific places.
Less powerconsumption, and pearhaps less algea also.
wouldn't that be great?
cheers
 
Hi Clone,
Thanks for making this article quite interesting as well as very informative for all of us..For your questions i would like to answer one by one..

1. Are you sure the heatsink will handle so dense population of LEDs? any calculations? Usually the heatsinks are rated by heat dissapation and LEDs by heat irradiation
Click to expand...

The Current Led fixture iam using is being running for the past six months,So Heat dissipation's are very well managed.

2. Why you need Cyan/Green
Click to expand...

Well this is a topic of interest i have,the idea of cyan came from seeing different commercially available Led fixtures showing promising results such as Illumagic LEDs & Maxspect R420r,where they claim usage of color combination are worth it.
Any how i am pretty much satisfied with those graphs you have posted for cyan.

3.Colour balance?????? it is difficult to say really
Click to expand...

Yes you are absolutely right about color balance it may differ from person to person, depending on their choice of Plants.I personally feels hobbyists opt for enhancement of natural color of plants ie.. more reddish hue for red plants & same for green.

As per your recommendation, My config would be 55x1w of 6500k ,18x1w of Royal Blue 450nm & 18x1w of Red 625nm

I have just made an vector combination using all

6HoGz4W.png


Please suggest whether this particular pattern can be followed..

Cheers
 
Hi, sorry for the delayed answer, been bisy for awhile. That is my sugestion for the LEDs.
6HoGz4W.png

I know 16x blue and 16x red, but looks alot neater and I bet colour mixing will be smooth and uniformal the whole lenghth of the fixture. Dont know abou how will wire tehem????
You said you runned the light already for months so....keep us updated;)[DOUBLEPOST=1397257422][/DOUBLEPOST]Dont forget to use pull resistors .......what will be your voltage??? Having so many leds no matter in series ar paralel ...will cause what I have called V drop :D In overclocking language means that volts seem not to be enough for the power consumpted from the semiconductors -Processor, graphics etc. as the LEDs..that happens when you OverClock you computer and your PSU is not strong enough...so the OC is not stable ..the result is blue screen :arghh: and milion restarts of the PC. Sorry that might be off topic...but!!! I have noticed the same with the LEDs ...can anyone with more semiconductors knowledge can confirm that, please?:bookworm:
 
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Thanks for the reply Nikolas..:)

I got a suggestion from Aquaticplantcentral it says "Your 6,700K LED's if properly advertised are already strong in blue light but are weak on the red end of the spectrum. By adding 620nm LED's you will build up the red end of the spectrum. But a little red in LED power goes a long way so you do not need a lot of additional RED. On a 96 bulb fixture I would probably include about 8 Red LED's but no more than 12.":crazy:

As my existing fixture were fully equipped with 6700k LEDs, which they claim to provide sufficient blue spectrum to the entire aquarium..Should i reduce the royal blue Led numbers or keep the same as u suggested...

Its my fault i had mentioned them wrongly 6500k instead:( of 6700k Leds..

Please guide me as am on their final stages of procuring them .

Thanks
 
Only your eyes can tell you about the light 6500_6700 its not big difference, extra blue light is always beneficual as long as your white light is not too bluish. White light priduced by LEDs is mixture of blue and yellow anyway, there are not white LEDs. So your 6500k will look yellow, 6700k may be bluish. I will keep the number of LEDs as adviced on my previous post. If u think whites are bluish reduce the riyal blues, but not the reds.

Sent f
rom my ST18i using Tapatalk 2
 
Oh, and forgot to mention red light is strongly absorbed by the water, the aquatic plants already know that and use more the blue light to photosynthesise, especialy in the ocean. So red light is never enough

Sent from my ST18i using Tapatalk 2
 
clone said:
the aquatic plants already know that and use more the blue light to photosynthesise, especialy in the ocean. So red light is never enough
Click to expand...

This is completely false. Yet another reason the OP is wasting his time worrying about blue or red. Plants do not really care what color light is available.

Cheers,
 
ceg4048 said:
This is completely false. Yet another reason the OP is wasting his time worrying about blue or red. Plants do not really care what color light is available.
Click to expand...
With all my respect, try to grow plants under green bullb/leds and will see the result. I have the same plant growing in two different tanks as I dose the same ferts and use the same substrate with the only difference of light colour and intensity, where above one of the tanks there are red and blue LEDs and the plant has red coloration , and in another tank the leds are just 6400K LEDs where the plant staing leggy and green....so??? Does different colours in the light spectrum play any role in the rate of photosynthesis of the aquatic plants?
 
clone said:
http://www.scuba-tutor.com/dive-physics/water-density/color-absorption.php
Click to expand...
Nikolas,
Have you actually looked carefully at the data in that link? This is one of the reasons people waste time while pulling information. The information is valid, but the application of the data has no relevance to the hobby. Review this statement carefully. I've pulled it from the link:
A useful way to remember this order is "ROY-G-BIV." Red and orange are absorbed at about 20 feet, while blue, indigo, and violet are absorbed far beyond maximum diving depths
Click to expand...
Now, is your tank 20 foot (6 meters) tall?
I don't think so.
If your tank is only 2 feet tall then this data is irrelevant and does not apply. Planted tanks never have to worry about spectral absorption...ever. So if you develop plans of action based on this data then you will be wasting time and energy.

It's a very similar situation with the color absorption of the pigment cells. Yes there are demonstrated growth performance differences at specific wavelengths when those wavelengths are isolated. In fact, as it turns out the isolated color that has the best performance is Red, not Blue as you have imagined. So just because there are chlorophyll charts that show the response curves to incident light, it is too narrow a view to only look at that data and to draw conclusions based on the response curve. So in fact, what you are suggesting is completely wrong - if we were interested in having a single wavelength illuminating the tank.

As it turns out, all white bulbs have a bit of each color and the PAR falloff is not even close to the absorption charts you link to, so we really never need to think about Kelvin or having enough blue bulbs or red bulbs. it a completely academic excercise which has no real bearing in actual tanks. The OP should design his lighting fixture so that he will achieve the best visual appeal, so this actually includes having yellow and green and orange and purple so that the tank will not look too sterile. In fact it is highly likely that the fixture will have too much PAR and the OP will struggle mightily with algae and other plant health issues. He should be busy designing a competent method of CO2 flow and distribution methods, because that is a lot more important than what color diodes are being used.

See all the arguments hashed out in the thread http://www.ukaps.org/forum/threads/spectrum-doesnt-matter-does-it.26717/
where there is a link to some tests done showing yield as a function of specific wavelengths.

Cheers,
 
Hi, Clive and thanks for the answer, you knowledge and opinion has ben always valuable for me. As we read and research any data on anything in internet and books we try to bend it always trough the prism of our hobby, so i totaly agree that the tank is not 6meter deep, but also the LED fixture is not the SUN. I think water is water no matter in the Ocean, Lake or fish tank at home , will always absorb red specrum the most. And yes the purpose of light is firstly to iluminate our tanks so we can see it in all their colours, and then to possibly grow plants. As living oraganism plants are highly adaptable to the environment, so I bet HC will grow in almost dark conditions, but that is not the point. CRI of all LEDs is poor I use Osram Oslon which claim to have 95CRI and 6400K colour temp, they grow plant in good rate but the red plants do not colorate as my other tank with red/blue leds.....just a RAW experience. It is Kingdamm decision if he wants blue, green, UV or X-ray diodes......I`am clearly not saying that my opinion is the most valuable at all......Thanks
 
I cant understand this .. As per ceg4048 views the various wavelength & colour temperatures doesnt have any effect on the growth rates & their coloration..
I have been using my DIY fixture which consists of 6700k leds 96w in total output over my 70 gallon tank.I cant make my plants stay redder...i tried to reduce lean nitrate,but miserably failed...



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vyva2yvu.jpg


Tombarr claims to have used these wavelength bulbs to achieve something quite outstanding..

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