DIY LED lighting MH replace

[Qwiv]

<a href=showthread.php?s=&postid=8096983#post8096983 target=_blank>Originally posted</a> by WarrenG
Looking at the link I did not find any plots of the spectrum graphs for their LED's.

Also, if the spectrum is very peaked, and is missing some colors, like yellow, or red, or purple, or orange, then that LED will not render that color very well.

Interesting info here...

http://www.wetwebmedia.com/ca/cav1i4/fluorescent_lamps/fluorescent_lamps.htm

MH, Florecent and all other lights we use don't minic the sun in terms of spectrum. Not even close. The LED's do a worse job as the light is very narrow in terms of spectrum. But recreating the sun is not the point. Building a light that will grow corals/look nice and run cool/low energy is the point. With the right mix of LED's this is possible. I will tell you that the light I get is not as good as the MH/T5 combo on my display tank, but I can also tell you that it grows corals just fine. If you read the article you linked to, they showed that the photosynthesis in coral from the sun and the 20k bulb where about the same given = PAR. That means that the spectrum is not as important to coral growth as getting enough energy (PAR).

 

[Qwiv]

<a href=showthread.php?s=&postid=8097181#post8097181 target=_blank>Originally posted</a> by pulse13
Oops I thought their datasheets had the spectrums, this link for the Luxeon K2 datasheet on p. 12 has the spectral plots:

http://www.lumileds.com/pdfs/DS51.pdf

Thats why I'm still debating using RGBLEDs, they have a red peak at 625nm which renders deep red well but not yellow-orange,orange or red-orange. Adding in red-orange LEDs ~595nm would help.

I think the RGB LED's are a bad idea unles you are trying to make a disco fish tank with crazy mood lighting. You are investing in all these LED's that you will dim to make the tank the color you like but will still have all the power supply to light these LED's 100%. So, say there are 30 LEDs, 10 red, 10 green, 10 blue. You have the red dimmed to 50%, Green 60%% and Blue at 100%. The dimmed LED's are wasting space, plus the Red and Green LED's stink on PAR.

If I had the cash to throw at it, I would buy one of the RBG led. Adjust it to the color I liked then purchased the individual LED's in the ratio determined by experimentation for the rest of the tank. I played with a bunch of the LED's. The Blue and White ones are the best combo. I have (2) red ones as well to warm it up a bit and use as night lights.

 

[pulse13]

The reason I've been thinking about an RGB system for an aquarium is it allows you to fine tune the color. White LEDs have a lot of variation in color tint between LEDs, therefore they have an elaborate binning structure. See the Lumileds binning structure here:

http://www.lumileds.com/pdfs/AB21.pdf

This link has a color chart showing binning structure for white Luxeons:

http://home.comcast.net/~theledguy/bin_codes/index.htm

Unfortunately, its hard to obtain large quantities of LEDs of a specific bin. Specific bins are available from people who buy LEDs in large quantities and sort out the good bins, but they can be very expensive. I paid ~$15 each for white Lux IIIs of a specific bin that I wanted for a flashlight mod. Authorized dealers will not tell you what bins you will receive in your order.

The RGB Atlas I have for the most part renders colors in corals very well, probably since most of the color is from fluorescence and not from reflected and scattered light. It will make a bright yellow fish look orange however. Maybe what I need is a mix of phosphor white and RGB LEDs. I'm going to wait until I actually see a Solaris fixture before I decide on my setup (an lfs here has one on order for a store display).

I'd also like to see how Cree 3w UV LEDs (~400nm) look added in with the Solaris fixture. I don't like very blue looking tanks, and having actinics increases fluorescence without making the tank look as blue. I'm concerned about the Solaris lacking spectrum < 450nm that actinics help to fill in. Also I believe the blue LEDs in the Solaris are ~470nm, while royal blue LEDs ~450nm are available.

 

[pulse13]

Qwiv, thats a good suggestion. I was writing my last post when you posted yours

 

[WarrenG]

<a href=showthread.php?s=&postid=8097321#post8097321 target=_blank>Originally posted</a> by Qwiv
MH, If you read the article you linked to, they showed that the photosynthesis in coral from the sun and the 20k bulb where about the same given = PAR. That means that the spectrum is not as important to coral growth as getting enough energy (PAR).

Intensity is important, but many individual species/types of corals in the wild self-select to grow within fairly narrow ranges of depth, which is essentially the same as saying that they self-select the range of light color they prefer.

When you go in areas with less light transmission to depth (like some lagoons) you can have similar light colors but lower intensity of light. But I don't find (many) corals moving up into the shallower water (to make up for the loss in intensity). I think that's because the light color isn't optimal at the shallower depth.

You can also see this in some areas where vertical walls provide shade (limit the light intensity) but the color of the light hasn't changed.

 

[Qwiv]

<a href=showthread.php?s=&postid=8097660#post8097660 target=_blank>Originally posted</a> by WarrenG
Intensity is important, but many individual species/types of corals in the wild self-select to grow within fairly narrow ranges of depth, which is essentially the same as saying that they self-select the range of light color they prefer.

or PAR requirments!

Reefers who care select the corals that grow under their lights or select lights that grow their corals. Unless you have 15 different lights over your tank, what is your point?

When you go in areas with less light transmission to depth (like some lagoons) you can have similar light colors but lower intensity of light. But I don't find (many) corals moving up into the shallower water (to make up for the loss in intensity). I think that's because the light color isn't optimal at the shallower depth.

There could be many other reasons why corals don't move into the shallows of lagoons such as temp swings which is much more likely.

You can also see this in some areas where vertical walls provide shade (limit the light intensity) but the color of the light hasn't changed.

Or the coral prefers shade/less PAR. I don't know how you have you tank lights planned, but this thread is about making a LED light to replace a MH, not the sun. There is no light that duplicates the sun and LED's aren't going to do it. Yes, some corals prefer certain spectums, can you give me a list of what corals prefer what spectrum so I can make my light better:rolleye1: I will put the perfect LED over every coral! :lol:

 

[easttn]

I wrote an exhaustive binomial linear regression model to skirt the issue of the LEDs binning supply chain problem. It is monochromatic only at this time. Basically I can arrange an array of LEDs of given bins at hand and determine a specific chrominance and luminance at some distance X from the source. It uses the CIE chart to correlate the specific color. The only bin that must be the same in each array is Vf. You should aim for the max in luminance, but I can deal with shades of monochromaticity.

 

[pulse13]

The Vf bin doesn't matter if you drive them using current regulation and wire in series, you just have to make sure the driver can handle the total voltage of the series string.

 

[bebitte70]

Tagging along...

 

[easttn]

<a href=showthread.php?s=&postid=8102185#post8102185 target=_blank>Originally posted</a> by pulse13
The Vf bin doesn't matter if you drive them using current regulation and wire in series, you just have to make sure the driver can handle the total voltage of the series string.

I agree, but I did not like the limitations of a series string through a 2'x6' area. Multiple series strings in parallel are the most efficient. Vf considerations in this scenario are prudent.

 

[bebitte70]

So any pics available?

 

[drinkhomebrew]

<a href=showthread.php?s=&postid=8061895#post8061895 target=_blank>Originally posted</a> by xtrstangx
Sounds awesome, but...

Fark.com
?

 

[toastman]

I have to agree....where are the pics.....lol...you can spend that much on LEDs you need to spend another 75 bucks on a digital camera...j/k .... but come off the pics please

 

[TandN]

taggin along

 

[marcwake]

tagging along as well.... we need some pics of your PIC

 

[tulkas71]

Please people.
At the bottom of the page is a button that says reset form.
If you look below that is a link that lets you subscribe to this post without having to "Tag along"

Thanks in advance