The Planted Tank Forum - Reply to Topic
Planted Tank Forums
Your Tanks Image Hosting *Tank Tracker * Plant Profiles Fish Profiles Planted Tank Guide Photo Gallery Articles

Go Back   The Planted Tank Forum > Specific Aspects of a Planted Tank > Lighting > DIY led lighting - have I got it right before purchasing

Thread: DIY led lighting - have I got it right before purchasing Reply to Thread
Title:
  
Message:
Post Icons
You may choose an icon for your message from the following list:
 

Register Now

In order to be able to post messages on the The Planted Tank Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Additional Options
Miscellaneous Options

Topic Review (Newest First)
01-23-2013 12:23 PM
csf V=IR and P=IV (I=current, V = volts, R = resistance, P = power).

Yes, the CREEs can be more efficient. That's why they are more expensive.

I don't know how linear the LEDs are with regards out input and output. Resistance can change. My general guess is they are somewhat linear until you get near max output, and then they saturate. Extra additional input equals to less additional output.

Quote:
Originally Posted by ced281 View Post
Anyone know how to calculate the lumens per watts for these? Will a 5W Cree really run at 5W if you're only running at 700mA instead of it's max 1.5A?

From back in my high school days, P=IV so Power = Current * Voltage. I'm assuming that the voltage doesn't change for these guys so if you decrease current the power (wattage) should decrease proportionally.
> So the power consumption of a 5W Cree running at 700mA is closer to 2.3W.
> Which means the lumens per watt is ~113
> Whereas the lumens per watt of these "high-power" Chinese LEDs are ~60 (180lumens/3W)
> Which means the efficiency of the Crees is almost 2x!
Does that make sense???
01-14-2013 10:05 PM
ced281
Quote:
Originally Posted by -Az- View Post
that's some real food for thought ced
thanks

I was just reading the red spectrum causing algae. also plants (and coral) have adapted to their natural depth which means that too much red can be detrimental.

i understand what you're saying about the visual aspect of the yellows and greens.
it still amazes me that the colour things appear is the colour they're not.

i think i'll stay with my reef capable amount of blues but play with my wiring so that blues, whites, pur colours and aesthetic colours can be controlled and dimmed separately. thus i can have whatever temp/spectrum i need.

what i love about the diy led approach is that if i think i'm short of red or whatever i can just add a couple of LEDs and problem solved.

i haven't ordered yet but i shouldn't be far off. just finalizing some details.

let us know how your build goes. are you using dimmers?
Ideally I'd like to use dimmers but I'm trying to maintain a budget right now. I have 4 non-dimmable and 2 dimmable drivers but I'm not sure the dimmable drivers work. If they do, I'll have dimming capabilities for 1/2 of my LEDs (currently planning for 4x13 strings of 3W LEDs @ 700mA).
01-09-2013 08:52 PM
-Az- nice info
it would be fascinating to study.
slightly off topic. there are some amazing living sculptures using plants that are trained.
people are even weaving saplings to make walls and houses as they grow to trees.
nature is awesome.
01-07-2013 05:06 PM
TexasCichlid
Quote:
Originally Posted by Build My LED View Post
Hi Az. Since plants are not able to choose their home, they have become extremely good at adapting to their immediate environment in order to increase their chances of survival. One of the best ways they do this is by using their Phytochrome proteins to sense their environment. This category of photobiology is called photomorphogensis. This is completely different than photosynthesis, but it is a very important part of the plantís lifecycle. With photosynthesis, we are focused on using the right type and right amount of light to grow the plant. With photomorphogenesis, we are focused on using specific light signals (photo) to impact the plants development (morphology). The Phytochrome gets a lot of attention, but we should also be aware of the Cryptochromes and Phototropins, as they both play an important part in plant development.

Back to your original question, I donít pay too much attention to the Red to Far Red (R:FR) ratio for most lighting applications, since most people are focused on Photosynthesis (i.e. bigger plants). If you are trying to induce a Phytochrome-related response (i.e. induced flowering, delayed flowering, taller plants, etc.), then you need to pay attention to the R:FR ratio. Per my earlier post, green and far red (especially far red) are transmitted through the plant canopy at a higher rate than blue and red. Over time, plants have figured out that a high level of far red light probably means they are being shaded by taller plants. Since they need light for photosynthesis, the plants realize they need to shift their energies into growing taller to get above the other plants. If they donít, they probably wonít survive very long. Once above the canopy, the R:FR ratio changes, and the Phytochromes tell the plant to stop growing tall/spindly, and to put their energies back to growing more leaves/branches to catch more light for photosynthesis. This is called the Shade Avoidance Response, and it is a really interesting facet of photobiology. As mentioned, you can also use 660nm and 730nm to induce or suppress flowering in short day plants (SDP) and long day plants (LDP). I have worked on large commercial photomorphogenic lighting applications, and it is really amazing stuff.



Hope that helps



Nick
That you for the informative post Nick. I did not know any of that.
01-07-2013 04:43 PM
Build My LED
Quote:
Originally Posted by -Az- View Post
Nick,
what are your thoughts on the red to near red ratio?

i think I read somewhere in can be used as a way to measure PUR.

more importantly, i've just been doing some reading on phytochromes and was interested in this.

"Finally, phytochrome allows plants to detect the spectral quality of light, a form of color vision, by measuring the ratio of Pr to Pfr. When a plant is grown under direct sun, the amounts of red and far-red light are approximately equal, and the ratio of Pr to Pfr in the plant is about 1:1. Should the plant become shaded by another plant, the Pr/Pfr ratio changes dramatically to 5:1 or greater. This is because the shading plant's chlorophyll absorbs much of the red light needed to produce Pfr and absorbs almost none of the far-red light used to produce Pr. For a shade-intolerant plant, this change in Pr/Pfr ratio induces the plant to grow taller, allowing it to grow above the canopy."
McGraw-Hill Encyclopedia of Science and Technology

mmmm
does this mean with 2%far red we should only have equal 660nm.
if we increase both to the 20-40% range would that be detrimental.
maybe a balance. down to 7-15% for both.

what does every one think??
I'd be keen to hear your thoughts Nick.
Hi Az. Since plants are not able to choose their home, they have become extremely good at adapting to their immediate environment in order to increase their chances of survival. One of the best ways they do this is by using their Phytochrome proteins to sense their environment. This category of photobiology is called photomorphogensis. This is completely different than photosynthesis, but it is a very important part of the plantís lifecycle. With photosynthesis, we are focused on using the right type and right amount of light to grow the plant. With photomorphogenesis, we are focused on using specific light signals (photo) to impact the plants development (morphology). The Phytochrome gets a lot of attention, but we should also be aware of the Cryptochromes and Phototropins, as they both play an important part in plant development.

Back to your original question, I donít pay too much attention to the Red to Far Red (R:FR) ratio for most lighting applications, since most people are focused on Photosynthesis (i.e. bigger plants). If you are trying to induce a Phytochrome-related response (i.e. induced flowering, delayed flowering, taller plants, etc.), then you need to pay attention to the R:FR ratio. Per my earlier post, green and far red (especially far red) are transmitted through the plant canopy at a higher rate than blue and red. Over time, plants have figured out that a high level of far red light probably means they are being shaded by taller plants. Since they need light for photosynthesis, the plants realize they need to shift their energies into growing taller to get above the other plants. If they donít, they probably wonít survive very long. Once above the canopy, the R:FR ratio changes, and the Phytochromes tell the plant to stop growing tall/spindly, and to put their energies back to growing more leaves/branches to catch more light for photosynthesis. This is called the Shade Avoidance Response, and it is a really interesting facet of photobiology. As mentioned, you can also use 660nm and 730nm to induce or suppress flowering in short day plants (SDP) and long day plants (LDP). I have worked on large commercial photomorphogenic lighting applications, and it is really amazing stuff.



Hope that helps



Nick
01-06-2013 07:26 PM
mistergreen good to know that green light is important too.
It makes sense plants that are red, brown would need more green light.
01-06-2013 10:29 AM
-Az-
Red to Far Red Ratio

Nick,
what are your thoughts on the red to near red ratio?

i think I read somewhere in can be used as a way to measure PUR.

more importantly, i've just been doing some reading on phytochromes and was interested in this.

"Finally, phytochrome allows plants to detect the spectral quality of light, a form of color vision, by measuring the ratio of Pr to Pfr. When a plant is grown under direct sun, the amounts of red and far-red light are approximately equal, and the ratio of Pr to Pfr in the plant is about 1:1. Should the plant become shaded by another plant, the Pr/Pfr ratio changes dramatically to 5:1 or greater. This is because the shading plant's chlorophyll absorbs much of the red light needed to produce Pfr and absorbs almost none of the far-red light used to produce Pr. For a shade-intolerant plant, this change in Pr/Pfr ratio induces the plant to grow taller, allowing it to grow above the canopy."
McGraw-Hill Encyclopedia of Science and Technology

mmmm
does this mean with 2%far red we should only have equal 660nm.
if we increase both to the 20-40% range would that be detrimental.
maybe a balance. down to 7-15% for both.

what does every one think??
I'd be keen to hear your thoughts Nick.
01-06-2013 09:31 AM
-Az- great info Nick
thanks for sharing your expertise
01-06-2013 03:10 AM
Build My LED
Quote:
Originally Posted by ced281 View Post
I think you're right about the generic LEDs being less efficient at converting watts to lumens than the crees. But I think you can partially work around that by buying the "high power" LEDs which are supposedly rated at 160+ lumens. Here are 3W LEDs from China which generate 170-190 lumens.

[Ebay Link Removed]

If you look at the specs for the Cree XP-G's their 5W LEDs generate 260 lumens at 700mA.

http://www.cree.com/~/media/Files/Cr...g/XLampXPG.pdf

Anyone know how to calculate the lumens per watts for these? Will a 5W Cree really run at 5W if you're only running at 700mA instead of it's max 1.5A?

From back in my high school days, P=IV so Power = Current * Voltage. I'm assuming that the voltage doesn't change for these guys so if you decrease current the power (wattage) should decrease proportionally.
> So the power consumption of a 5W Cree running at 700mA is closer to 2.3W.
> Which means the lumens per watt is ~113
> Whereas the lumens per watt of these "high-power" Chinese LEDs are ~60 (180lumens/3W)
> Which means the efficiency of the Crees is almost 2x!
Does that make sense???



Some of the limitations of light penetration by lower wavelength colors can be somewhat dealt with by using more focused beams (who knows how much it can be avoided though).

Having greens and yellows can be argued to be "wasted" light because they don't aid in photosynthesis, but the more green and yellow light you send into the aquarium, the more those colors will shine off your plants and into your eyes.

I would be careful about having too many red likghts. I read somewhere (I think in the lighting sticky) that algae is better at utilizing red than blue light, so having high levels of red light without proper plant load could be conducive to algae blooms, etc.

More food for thought! Let us know what you're planning.

If I end up having more free time I might start up a thread documenting my DIY lighting for my DoAqua 90P tank. I just got my makersled fixtures and am waiting on my LEDs from China =]
Hey guys/gals. I wanted to chime in here on a few of these topics, as there is so much misinformation concerning LEDs and spectrum related to plant growth on the Internet. Before I started Build My LED, I managed a horticulture lighting division for an LED manufacturing company. We competed against all of the global LED companies (i.e. CREE, Philips, Bridgelux, etc.), so I have some direct experience in this segment. Having said that, I am not a planted tank expert I do know lighting and LEDs, so together, we should be able to help move the ball forward.

Concerning Lumens per watt. First of all, you need to compare apples to apples when comparing LEDs. LED manufacturers don't have a consistent method to publishing these numbers, so you need to dig into the spec sheets. Most companies publish this metric by flashing the LEDs with a 20 millisecond pulse of electricity. The LEDs are ‘cold’, so they are very efficient during the test. If you would test that same LED 10 seconds later, it would produce a lower Lumen number, since LEDs produce less light as they heat up. If you would test that same LED after it has been sitting over an aquarium for three hours, you would have an even lower number. While on this topic, it is important to note there can be significant losses with the optical and electrical systems in any lighting system. By the time you consider all three levels of losses (thermal, optical and electrical), the overall fixture efficiency is nowhere near the values published for the bare LED.


Concerning the green/yellow light, wasted energy issue. In summary, this is the worst myth on the Internet concerning horticulture lighting and photobiology. As long as photons between 400 and 700nm are absorbed, they are useful for photosynthesis. There are no wasted wavelengths in this band of light (electromagnetic radiation). Here is how the myth is usually propogated: “Plants are green, so they are reflecting the green light back to your eye, so the plants are not using it. Hence, green light is wasted energy. “ Scientifically, this is absolutely wrong. Green light is very useful to plants, it just doesn’t get absorbed by the chloroplasts as efficiently as blue and red light. Hence, the plant appears green. However, it is not reflecting all of the green light, and green light even has some advantages over red and blue light. Green light (and far red light) can penetrate deeper into the plant canopy, so spectra with green light usually outperform spectra that only contain red and blue light. In fact, NASA published a paper concerning this issue in 2004, and the green-enhanced light actually grew 45% more biomass than the red and blue spectra.

Finally, Kelvin is basically a useless metric for comparing different light sources, as it does not define a single color. In other words, you can buy a 5700K light from 20 different companies, and they will all look different, even though they are all correctly labeled 5700K. Google the 1931 CIE color chromaticity diagram, and you will see vertical black lines near the center of the chart. These vertical lines define the specific color temperatures (i.e. 5700K), and you will notice how they stretch from the pink region into the green region. That is why you will see so much variation while comparing lights based on the Kelvin scale. Alternatively, I recommend you look at the actual spectrum of light, as this is what is used to calculate the Kelvin temperature. By looking at the spectrum power distribution (SPD) chart, you will be in a much better position to compare various light sources for horticulture applications.

I hope this helps ‘shed some light’ on the subject on LEDs and horticulture lighting. This wasn’t meant to be a comprehensive dissertation on the above topics, but I wanted to chime to add my two cents to the discussion :-)

Nick
01-05-2013 04:34 PM
Steve001
Quote:
Originally Posted by -Az- View Post
that's some real food for thought ced
thanks

I was just reading the red spectrum causing algae. also plants (and coral) have adapted to their natural depth which means that too much red can be detrimental.

i understand what you're saying about the visual aspect of the yellows and greens.
it still amazes me that the colour things appear is the colour they're not.

i think i'll stay with my reef capable amount of blues but play with my wiring so that blues, whites, pur colours and aesthetic colours can be controlled and dimmed separately. thus i can have whatever temp/spectrum i need.

what i love about the diy led approach is that if i think i'm short of red or whatever i can just add a couple of LEDs and problem solved.

i haven't ordered yet but i shouldn't be far off. just finalizing some details.

let us know how your build goes. are you using dimmers?
Take a look at this thread's photos using custom leds.
http://www.plantedtank.net/forums/sh...t=#post2148737
01-05-2013 10:22 AM
-Az- that's some real food for thought ced
thanks

I was just reading the red spectrum causing algae. also plants (and coral) have adapted to their natural depth which means that too much red can be detrimental.

i understand what you're saying about the visual aspect of the yellows and greens.
it still amazes me that the colour things appear is the colour they're not.

i think i'll stay with my reef capable amount of blues but play with my wiring so that blues, whites, pur colours and aesthetic colours can be controlled and dimmed separately. thus i can have whatever temp/spectrum i need.

what i love about the diy led approach is that if i think i'm short of red or whatever i can just add a couple of LEDs and problem solved.

i haven't ordered yet but i shouldn't be far off. just finalizing some details.

let us know how your build goes. are you using dimmers?
01-05-2013 07:30 AM
ced281
Quote:
Originally Posted by -Az- View Post
cheers mate.

I'll do a little digging on the ratios.
I've written down in my notes that 1rb:1cw = 10000-12000k ( I haven't noted where I got that info from).
the addition of the extra cool whites (5000-8300k) should soften the effect. can anyone confirm if I've got this right?

I'll have a look at the cheap LEDs. from my understanding the crees put out more light using less energy ( thus meaning less driving power for each string or more LEDs)
as well as what you mentioned with the accurate wavelength peaks. if the led peaks at the wrong wavelength then it potentially could be useless to plants become purely mood lighting ( eg red (670nm) and far red (730nm which is outside PAR).
I think you're right about the generic LEDs being less efficient at converting watts to lumens than the crees. But I think you can partially work around that by buying the "high power" LEDs which are supposedly rated at 160+ lumens. Here are 3W LEDs from China which generate 170-190 lumens.

[Ebay Link Removed]

If you look at the specs for the Cree XP-G's their 5W LEDs generate 260 lumens at 700mA.

http://www.cree.com/~/media/Files/Cr...g/XLampXPG.pdf

Anyone know how to calculate the lumens per watts for these? Will a 5W Cree really run at 5W if you're only running at 700mA instead of it's max 1.5A?

From back in my high school days, P=IV so Power = Current * Voltage. I'm assuming that the voltage doesn't change for these guys so if you decrease current the power (wattage) should decrease proportionally.
> So the power consumption of a 5W Cree running at 700mA is closer to 2.3W.
> Which means the lumens per watt is ~113
> Whereas the lumens per watt of these "high-power" Chinese LEDs are ~60 (180lumens/3W)
> Which means the efficiency of the Crees is almost 2x!
Does that make sense???

Quote:
Originally Posted by -Az- View Post
thanks for doing that steve

there seems to be a lot of yellow and green in the spectrum (wasted energy?)

i'm still concerned with the kelvins ( in regards to penetration)

"It is also noteworthy that many "terrestrial plant lights" as well as many aquarium plant lights (often are lower in kelvin temperature) have more "red nanometer spikes" than higher kelvin 6500k, 10,000k & higher lamps.
The problem with these lights is that while all plants utilizing photosynthesis require the same essential ABCs of PAR (see the PAR section), the facts of light energy penetrating water requires higher kelvin (6500k +) be added to provide maximum PUR (see Useful light energy/PUR section). Aquatic Plants and corals have adapted/evolved to the natural light energy at certain depth of water and the misguided attempt to adapt these terrestrial plant lights is not going to be 100% effective as a light with more water penetrating blue & slightly lower red nm energy."
aquarium lighting by carl strohmeyer

I,m starting to think about adding some reds in strategic locations about the substrate
Some of the limitations of light penetration by lower wavelength colors can be somewhat dealt with by using more focused beams (who knows how much it can be avoided though).

Having greens and yellows can be argued to be "wasted" light because they don't aid in photosynthesis, but the more green and yellow light you send into the aquarium, the more those colors will shine off your plants and into your eyes.

I would be careful about having too many red likghts. I read somewhere (I think in the lighting sticky) that algae is better at utilizing red than blue light, so having high levels of red light without proper plant load could be conducive to algae blooms, etc.

More food for thought! Let us know what you're planning.

If I end up having more free time I might start up a thread documenting my DIY lighting for my DoAqua 90P tank. I just got my makersled fixtures and am waiting on my LEDs from China =]
01-05-2013 07:08 AM
ced281
Quote:
Originally Posted by Steve001 View Post
It certainly does give you a Kelvin rating and more. The K temp would be somewhere between 5500-5900 K
http://buildmyled.com/custom-report-...MCAOODGPPECQQS
Your a bit mistaken on the blue part for planted tanks. Blue light does penetrate the most but planted tanks need full spectrum all the way to the substrate.
That app is pretty sweet! I've looked at that site a couple of times but didn't notice this!
01-04-2013 11:02 PM
-Az- thanks for doing that steve

there seems to be a lot of yellow and green in the spectrum (wasted energy?)

i'm still concerned with the kelvins ( in regards to penetration)

"It is also noteworthy that many "terrestrial plant lights" as well as many aquarium plant lights (often are lower in kelvin temperature) have more "red nanometer spikes" than higher kelvin 6500k, 10,000k & higher lamps.
The problem with these lights is that while all plants utilizing photosynthesis require the same essential ABCs of PAR (see the PAR section), the facts of light energy penetrating water requires higher kelvin (6500k +) be added to provide maximum PUR (see Useful light energy/PUR section). Aquatic Plants and corals have adapted/evolved to the natural light energy at certain depth of water and the misguided attempt to adapt these terrestrial plant lights is not going to be 100% effective as a light with more water penetrating blue & slightly lower red nm energy."
aquarium lighting by carl strohmeyer

I,m starting to think about adding some reds in strategic locations about the substrate
01-04-2013 03:03 PM
Steve001
Quote:
Originally Posted by -Az- View Post
the app looks useful. cheers mate.
unfortunately i can't drop the LEDs onto the strip using my I-pad.
this means I'll have to venture upstairs to the civilised part of the house
i'm worried that it doesn't give a kelvin rating after adding blues.
while not being a factor in plant growth directly, kelvins is an important factor to penetration.
6500k at the surface means far less at the substrate.
for mid and cover plants apparently 8000k-10000k is needed.
most data out there is for a 24 in tank. all I can find is that if you have a deeper tank have more kelvins.
reefers need 14000k+ due to the fact that they need to replicate light conditions that are natural at many meters deep for coral growth.
It certainly does give you a Kelvin rating and more. The K temp would be somewhere between 5500-5900 K
http://buildmyled.com/custom-report-...MCAOODGPPECQQS
Your a bit mistaken on the blue part for planted tanks. Blue light does penetrate the most but planted tanks need full spectrum all the way to the substrate.
This thread has more than 15 replies. Click here to review the whole thread.

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


All times are GMT. The time now is 09:32 PM.


Powered by vBulletin®
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright Planted Tank LLC 2012