question about combining LED wavelengths

SnowManSnow · 08/18/2015, 08:57 AM

I'm trying to dial in 3 of the OR LED fixtures over a shallow tank, and i'm learning that less is more haha

I DO want to try and get a full spectrum out of these if possible but,

There are some omissions in the spectrum in these fixtures, namely under 420nm and around 6500k, so I'm thinking of doing a diy bar to hang between the fixtures to add these wavelengths.

here is what is in each of the 3 fixtures I am running. :

Red 660nm 2pcs
Green 520nm 2pcs
Blue 470nm 8pcs
Royal Blue 450nm 16pcs
Violet 420nm 6pcs
Cool White 12000K 8pcs
Cool White 10000K 6pcs
(144 LED lights over my 80g frag tank at 16" deep)

QUESTION... (and I'll use simple numbers)

IF I have a 10k bulb and a 5k bulb, and they are exactly that nm, and I run them at the same intensity, does that give me 15k yield, or do I still have 10k and 5k wavelengths ?

What do I need to add to this equation to give me a better chance of success?
Please don't say scrap the LED and do T5 or MH ha. :dead horse:
I'm a t5 man at heart, but I'm having a good time trying to figure the science of LED out.

SnowManSnow · 08/18/2015, 12:08 PM

anyone>
?
or is the question dumb haha

bapicella · 08/18/2015, 08:56 PM

I am interested to see the finished project. I like the idea of adding in an extra bar to fill the spectrum.

SnowManSnow · 08/19/2015, 04:37 PM

Quote:

Originally Posted by bapicella

I am interested to see the finished project. I like the idea of adding in an extra bar to fill the spectrum.

I can't seem to find an answer to the question at this point.... do the LEDS maintain their specific wavelengths when combined and it just LOOKS different, or does it actually change nm ?

oreo57 · 08/19/2015, 05:50 PM

Quote:

Originally Posted by SnowManSnow

I can't seem to find an answer to the question at this point.... do the LEDS maintain their specific wavelengths when combined and it just LOOKS different, or does it actually change nm ?

They maintain their wavelength..
color temp is additive but I won't really go into the colors..

Say you have whites in equal radiative amounts..
4000k and 10000k.. The effective CCT will be around 14000/2 = 7000k

White are usually RB plus phosphors to convert some blue to a more even spectrum.. more "red" phosphor lower K value..

RGB produce an "effective" white but spiky

Quote:

here is a comparison of typical LED spectra with the human eye’s response curve grayed out in the background. The curves are normalized so they’re all the same height.

whites:

for full spectrum you will need cyan.. see gap in whites:
Below is the discreet LED spectrums..

Ron Reefman · 08/20/2015, 06:38 AM

My question is, why do you want "full spectrum"?

Do you think it's going to improve something in the tank? Or is it just for your viewing pleasure?

ksicard · 08/20/2015, 07:25 AM

you said you were missing the 420nm wavelength but if I read your thread correctly it sounds like your current LED fixtures have violet 420nm already? If your going to do a DIY LED bar to supplement additionial wave lengths I would use full spectrum whites such as neutral whites, which are 4500k LEDs. And also maybe add some different spectrum blues or additionial violets to the DIY bar.

08/18/2015, 08:57 AM	#1
SnowManSnow Registered Member Join Date: Nov 2005 Location: Georgia Posts: 956	question about combining LED wavelengths I'm trying to dial in 3 of the OR LED fixtures over a shallow tank, and i'm learning that less is more haha I DO want to try and get a full spectrum out of these if possible but, There are some omissions in the spectrum in these fixtures, namely under 420nm and around 6500k, so I'm thinking of doing a diy bar to hang between the fixtures to add these wavelengths. here is what is in each of the 3 fixtures I am running. : Red 660nm 2pcs Green 520nm 2pcs Blue 470nm 8pcs Royal Blue 450nm 16pcs Violet 420nm 6pcs Cool White 12000K 8pcs Cool White 10000K 6pcs (144 LED lights over my 80g frag tank at 16" deep) QUESTION... (and I'll use simple numbers) IF I have a 10k bulb and a 5k bulb, and they are exactly that nm, and I run them at the same intensity, does that give me 15k yield, or do I still have 10k and 5k wavelengths ? What do I need to add to this equation to give me a better chance of success? Please don't say scrap the LED and do T5 or MH ha. :dead horse: I'm a t5 man at heart, but I'm having a good time trying to figure the science of LED out. __________________ It's dark as the inside of a cow out here! - Mark Twain Current Tank Info: 120 MRC acrylic Tank (love it). Constellation T5s Mixed Reef

08/18/2015, 12:08 PM	#2
SnowManSnow Registered Member Join Date: Nov 2005 Location: Georgia Posts: 956	anyone> ? or is the question dumb haha __________________ It's dark as the inside of a cow out here! - Mark Twain Current Tank Info: 120 MRC acrylic Tank (love it). Constellation T5s Mixed Reef

08/20/2015, 06:38 AM	#6
Ron Reefman Registered Member Join Date: Jul 2009 Location: Cape Coral, FL Posts: 10,431	My question is, why do you want "full spectrum"? Do you think it's going to improve something in the tank? Or is it just for your viewing pleasure? __________________ The good thing about science is that it's true whether or not you believe in it. (Neil deGrasse Tyson) Visit my build thread http://www.reefcentral.com/forums/showthread.php?t=2593017

08/18/2015, 08:56 PM	#3
bapicella Registered Member Join Date: Sep 2014 Posts: 56	I am interested to see the finished project. I like the idea of adding in an extra bar to fill the spectrum.

08/20/2015, 07:25 AM	#7
ksicard Registered Member Join Date: Aug 2012 Location: Atlanta, Georgia Posts: 538	you said you were missing the 420nm wavelength but if I read your thread correctly it sounds like your current LED fixtures have violet 420nm already? If your going to do a DIY LED bar to supplement additionial wave lengths I would use full spectrum whites such as neutral whites, which are 4500k LEDs. And also maybe add some different spectrum blues or additionial violets to the DIY bar.