Elaborate Overdone DIY LED Fixture Help/Advice

[HeisenbergReef]

Hey all,
So I'm planning out/building a led light fixture and need some advice on power supply to use and on resistors to put in each string to be sure the voltage is proper across each led. I'm building it using DWZM's DIY cat4101 drivers and will have pwm dimming control of each string via two DIY typhon controllers (some strings will be on the same pwm signals). The issue is that each string will not be having the same number of leds and thus, different needs of proper resistors for proper voltages.
Here is what I want:

1=4 Neutral Whites
2=4 Neutral Whites
3=2 470nm Blue
4=3 460nm Royal Blue
5=2 445nm Royal Blue
6=3 420-425nm Violet
7=3 405-410nm UV
8=3 400-405nm UV
9=3 505nm Cyan
10=1 670nm Deep Red

All driven at 700mA
All (except the red) are driven at the usual 3.2-3.6v, the red drives at 2.2-2.6v
I'd be willing to put both RBs, Both UVs, and both Whites each on one string if do-able or makes things easier.

I know I'll need one or a couple resistors in series in each string before the leds to create the correct voltage drop, but I'm reaching out to all the experts for some advice on the resistor selection and psu selection

THANKS!
Johnny

ps. I know this setup may sound a little annoyingly elaborate, but I want to be able to take full advantage of everything and tweak the lighting exactly to my liking!

[mockery]

Hey where did you get the UV's?

[JW65]

I would really like to see the way you plan to lay these leds out. It looks like it would be an awesome color combination.

[HeisenbergReef]

the 400-405nm uv i'm am going to get from satisled.com

the 405-410nm uv i'm going to get from ebay

and the 420-425nm i'm going to get from leddna.com

I haven't purchased the leds yet though, as I want everything planned out first. I really want a nice full coverage of the violet/blue/cyan spectrum.

[HeisenbergReef]

This is the layout I've planned out. It will be on probably around a 20" large heatsink from heatsinkusa.com and I don't plan on using any optics.

[HeisenbergReef]

So after thinking about this power supply choice some more, I wonder what the led experts' around here thoughts are on how they pick a power supply?

Should I be picking a power supply to most closely match my power consumption? If so, then I would want to go with a 15v 7A power supply to run 10 strings at 700ma such as this one. Or do I want a power supply that exceeds my needs? and by how much?

Using a power supply that is as close to my needs as possible would minimize the needs for resistors at the head of the strings for the proper voltage drop, but would the power supply generate too much heat running at its capacity?

[fishtankbroke]

I'm guessing that this is much too late to chime in but I would think that you would want to be as close to the proper voltage output and be alittle over sized on the capacity. The resistors you have to add are nothing but added heater so the less the better and PS sweet spots are normally in the 60 to 80% of max load range (big swag on the %). How did you determine your light selection and placement???

[fishtankbroke]

This is the type of graphic that shows what I trying to say...
http://www.anandtech.com/show/2624/3

[pwreef]

What tank is this going over? Those UV/Violet LEDs barely produce any light. You will need like 10 of them before you see anything, unless its total darkness and they are right on top of the water. If I were you I would get the LEDs first and try to fire them up with a simple battery to see what is what. I have a DIY fixture that I put together myself from Bridgelux LEDs and I can tell you that the red and the UV/Violet don't do much. But its fun to experiment! Good luck. :-)

[BonsaiNut]

I think people are going a little nuts on the blue end of the spectrum. For the record, two different types of chlorophyll: chlorophyll a and chlorophyll b. Each has two peaks of spectral usage - one in the blue and one in the red:

chlorophyll a: blue peak 440nm red peak 690nm
chlorophyll b: blue peak 460nm red peak 665nm

At peak, you want about 2-3x the intensity of blue versus red. Notice 2-3x - not 6x, not 12x. You've got 19 blue emitters and a single red emitter (neutral whites notwithstanding).

[TropTrea]

BonsaliNut The actual ratio between the ideal red light and blue light is very debatable. Amoungst multiple studies it has also been found the red light can be more harmull to some corals in excess than benificial.

What I find interesting about this set up the use of the UV LEDs. I have never seen anything clamining that light in wave lenghts shorter than 420 nm was benificial. Actual it is the shorter wave lenghts that are used in UV filteration that break down the walls of plant tissue.

[haysanatar]

I bought some red led's for my tank.. but I'm debating using more of a pink led as of now I think reds are going to be a bit too overwhelming we'll see..
definitely watching this thread I've got a working fixture but I think I'm going to try to throw more color in the mix.

[nemosworld]

Coral reefs love blue light. Corals actually use the blue light created when the water filters away the red first and then the green to feed an organism within their tissues. By the time a diver gets down to 50 or 60 feet the only portion of the light spectrum left in the water is blue! If you try to take underwater photos without a corrected flash attachment you'll quickly see the result! That organism in the coral needs blue light to produce sugars which in turn feed the corals. Few corals actually "eat" much of anything in the ocean. Effectively, they are largely being fed sugar by an algae living inside the tiny coral polyp which through photosynthesis utilize the blue spectrum. If you happen to be a coral reef aquarium keeper you already know this! That's why you added those actinic blue lights to your aquarium.

http://www.exoticrainforest.com/Will...ht%20kill.html

[APBonds]

I put 60 DIY leds on my tank, 24 royal blue 24 cool white 6 red and 6 blue. When I first bilt it I had 12 red leds and it was too much, the red messed with my eyes. I replaced 6 red for the 6 blue and I have a much better look to my tank. The lights have been on my tank for 4 months now and every thing is doing great. Only draw back is the lights are a little to much for lps and I have to shade them. This is a older picture but its with all the lights at full power.

[haysanatar]

has anyone noticed any color shift?
and for people that have red's and cyans has this corrected the shift?
my red's are more orange now.
and I just had a 24k gold chalice become an interesting goldish green color.. almost like a neon tarnishing copper its pretty but its not the same gold color.

[TropTrea]

One of the things to keep in mind is that LED lights are generally produce a more narrow color spectrum than say T-5 's or any other light source. So if you have a T-5 bulb at 450 nm your really covering a range from 420 nm up to 480. While a LED at 450 nm only covers a range between 435 nm and 465 nm. By using both a 450 nm and a 465 nm LED
you are covering the range from 435 nm to 480 nm.

Different corals fluoresce using different wavelengths. While it it true that a majority of them fluoresce from light between 417 nm and 485 nm there are some that need other wavelength. So regardless of what light source your using when you change to a different light source you will see some changes in some of your corals.

As we concentrate on the blues because they are the most important for photosynthesis we cannot completely ignore the rest of the color spectrum. In the case of the Gold Chalice there are probably several pigments in the coral that are fluorescing each absorbing and emitting different colors. If we change the balance between the light at the frequencies that the pigments are absorbing light we will also change the ration of the various wavelengths that these corals are fluorescing at.

In order to hit all these wavelengths one needs to combine different LED's as is the normal with most LED builds. However what should be kept in mind is that there are three different White LED's and of these there are various batches. Each of these have there own unique color balance. So it might be advisable that when your building a fixture to divide up the white LED's between more than one particular type.

I'm my build In considering the option of running more LED's at a lower current in order to give me more actual LED's and a more tunable balance.

[haysanatar]

as of now I have am running a combination of cool, nuetral, and warm whites, cool blue and royal blue. I HAD thought that my spectrum was going to be diverse enough... I'm currently looking into throwing some more led's in the mix specifically cyan purple red and i saw one pink one. I'm a tad curious about uv's aswell.. its not like corals don't ever get small doses of uv, and I've seen some literature saying that small doses of uv can make coral produce more pigments ( a coral tan).

[TropTrea]

UV lighting is very touchy. While it consists of the shortest wave length it can be attenuated drastically by just a thin layer of glass unlike longer wave lengths. How much UV lighting does coral get in the ocean is something I never saw anything written up on. But then I never saw any notes that lighting shorter than 380 nm is beneficial to any living creature.

The 400 nm to 420 nm that are listed as being UV are barely into the edge of the UV lighting range. Out of the LED combination listed above the most I would use is 2 of the 420 to 425 nm LEDS out of the 28 that were listed. I would not even bother the shorter wave lengths but would use more of the 460 nm Royal Blues.

Similarly I would not use a red LED but would split up my whites between 5,000 to 6,500K and the 3,500K. Yes you do need some red but excessive read can do more harm than good to some corals.

[haysanatar]

I do have mine split two strands of 14 running 5k one strand of 7 3500 7 650
2 strands royal blue 1 strand cool blue.
I saw one article that shows it COULD harm coral I was thinking of running 1 led per 2 foot section with no optics for aesthetics a little I guess..
On my old t-5s I was running a fiji pink and some violet and I really liked the more reddish purple actanic it made even leathers pop.
I've heard that cyan is very overpowering aswell any one tried using them?

[TropTrea]

Originally Posted by haysanatar

I've heard that cyan is very overpowering aswell any one tried using them?

With Cyan the secret is not to use enough that be become over powering. The eye is most sensitive to green light including the cyans and only a little cyan light will go a long long way.

[haysanatar]

have you used any?
Would 1 every 2 feet no optics be too much?

[wvreef]

uv light is needed to grow sps in our coral reef tanks....uv is suppose to be unseen by the human eye. mh put off uv and the glass blocks some but uv light still gets into the reef tank to get the growth for the corals....all corals need some type of uv light to grow...so we need to find out how much uv light is coming out of the mh light and match it with led uv bulbs to get the right growth for our corals....

[TropTrea]

Originally Posted by wvreef

uv light is needed to grow sps in our coral reef tanks....uv is suppose to be unseen by the human eye. mh put off uv and the glass blocks some but uv light still gets into the reef tank to get the growth for the corals....all corals need some type of uv light to grow...so we need to find out how much uv light is coming out of the mh light and match it with led uv bulbs to get the right growth for our corals....

Where did you get this information that corals need UV light from?

UVC light is 200 to 280 nm and is very harmful to most living organism. It is generally used in UV sterilizers.

UVB light 280 to 315 nm is considered harmful to flora and it is said to create bleaching or fading of the pigments in plants eventual killing them.

UVA light 315nm to 380 nm is claimed to of no value or benefit to photosynthesis.

The known wavelength absorbed for photosynthesis are 417 nm, 436nm, 447nm, 452nm, 475 nm, 485 nm, and 590 nm. However not all corals contain the
seven photosynthesis chemicals that use these wave lengths are found in all corals. As an example only in shallow water corals are some of the red wave length chemicals found, and in some deep water corals the red wave lengths in excess can be harmful.


For Coral Growth light below 417 nm is virtually useless. And even below 436 is of very little benefit compared to the range between 436nm and 485 nm.

However the florescence to give us some of the colors is another thing but still a majority of those chemicals are in the 440 nm to 578 nm.

Unfortunately if we lighted our tanks with just the needed wave lengths we would have a color balance that lacked red other than that created by florescence and most none fluorescing objects would would either greenish or blueish.

[wvreef]

I was going by the information listed under the color and wave lenght of MH bulbs per manufactures specs. All mh bulbs give off a degree of uv light which is needed for the coral to produce sugar to live on thru photosynthesis, without it corals would grow no or very very slowly in our tanks.... the ocean gets uv light in the reef all the time most is filtered out before it gets to the corals but not all because it is needed to produce the sugar the corals need to live on....
now i am going by what i have been told from someone that has been in the reef community for over 20 years and have tested the mh lights to see if they do give off uv light and they do to an point

just saying imop

[TropTrea]

Yes it is true that MH bulbs especially the newer dual ended bulbs do give off a good amount of UV lighting. This is why they warn that they need to be shielded since some of that UV lighting they are emitting is very dangerous and can destroy ones eyes as well as cause cancer. In most commercial MH bulbs used for aquariums a thin layer of glass is enough to filter out enough of the rays to make them safe.

However corals do not use this UV light under 417 nm to any measurable degree. If you believe everything that manufacturers claim on there packaging you can drive yourself craze. When I ad my shop several times I brought in new products based on the manufacturers data thinking I was getting something on the top of the line. But in reality it was only one step away from complete garbage.

There are several university web sites on line that have various PHD students graduate thesis. Many of those taking Marine Biology write about light in the oceans and corals. Browse through several of them some actually list the light frequencies used by corals for photosyntheses and even some of the florescent frequencies absorbed by corals. After viewing dozens of these I never found one listing a wave length under 417 nm as beneficial.

If some claims that wavelengths shorter than 417 nm are beneficial simply ask them which photosynthetic chemicals use these wave lengths, what specific wave length do they absorb, and what corals are these chemicals found in.