Guidance on LED color choices

[underseaalbert]

Hello all,

I´m newly come to the salty side of things and need some guidance on LED color choices.
I have a 15 gallon cube that will eventually have a few fish (3) some soft corals and some LPS. The aquarium comes with tube lighting and two blue leds for night lighting built into the hood. I´m going to ditch the hood and switch to LED in order to reduce temps during the summer and have the ability to run white and blue channels from individual timers (current set up won´t allow me to do this. )

The LED fixture that i´m looking at is a two channel (is that right?) dimmable 24x3W (blues and whites)
From doing a little reading on the forum i´ve seen other´s choices for colors but i haven´t seen any suggestions for 24 LEDs.

So far i gather based on what most suggest is that a 2:1 blue/white ratio is ideal using neutral whites and royal blues and adding some UV/Violets to the mix.

What i´m not clear on is how to distribute the colors.
Does one add the UV/Violets to the white channel or to the blue?
The extra blues go on the white channel, but should i stick with the royal blues for the extras or change to a different blue?

I´ve attached the layout that i was sent. I would greatly appreciate any input the experienced users could provide.

[Art13]

My best guess would be 6 4500k whites, 3 480 blue, 3 420 violets, possibly 1 660 red, 11 450 blue. I am going by a configuration leds that I have seen at a local reefer's house and he said he loved the light and growth. I know someone can chime in here and tweak/tear this apart and break down the reasons for it, maybe drop one 480 and one 420 and add two 450's. I think two channels would be best though, with the 450 blues on a separate channel.

[thegrun]

I would go with 8 white, 2 red and 2 green/cyan on one channel and 4 blue, 4 royal blue and 4 UV's on the other. For a bluer look simply dial down the white side in relation to the blue, but I think you will be happy with that overall color mix. That is a lot of light for a small tank so start off at very low percentages or you will burn your corals.

[underseaalbert]

Originally Posted by Art13

My best guess would be 6 4500k whites, 3 480 blue, 3 420 violets, possibly 1 660 red, 11 450 blue. I am going by a configuration leds that I have seen at a local reefer's house and he said he loved the light and growth. I know someone can chime in here and tweak/tear this apart and break down the reasons for it, maybe drop one 480 and one 420 and add two 450's. I think two channels would be best though, with the 450 blues on a separate channel.

Originally Posted by thegrun

I would go with 8 white, 2 red and 2 green/cyan on one channel and 4 blue, 4 royal blue and 4 UV's on the other. For a bluer look simply dial down the white side in relation to the blue, but I think you will be happy with that overall color mix. That is a lot of light for a small tank so start off at very low percentages or you will burn your corals.

Thank you both for taking the time to steer me in the right direction with this. Now i have more questions than i did before

thegrun, your option keeps a 1:1 blue/white ratio; i thought most people advocated a 2:1 ratio, any reason for this? is it because of the possibility of dimming between channels to adjust the color ratio?
What about the red/green mix? How well do these mix with the other colors? or am i going to get a christmas tree effect? I forgot to mention that the lenses are 90º spread.

I´ve done a quick color layout based on your suggestion. How does it look? I


Art13 Haven´t had a chance to put a layout based on your suggestion yet (still need to do this) Your option leans more towards the blue end of things and mixes the blues on both channels.
One led needs to go though as there are only 24 leds on this lamp.

[underseaalbert]

Just to add that whites, greens and reds are on channel 1. Blues and violets are on channel two.

Too much red? not enough blue? too much white? perhaps ditch two violets for royal blues?

Anyone care to critique?

[Art13]

My suggestion was based off a previous reefers and now my own setup, and that is also how then channels are split, you don't need a lot of whites to get the color your after, while they might help some with coral growth, I believe the majority comes from the one blue spectrum and the other spectrums all contribute but not as much, there is probably a wavelength diagram somewhere that will give you a better Idea of which spectrum is needed in what amounts, but again i have the 450 blues on their own, 44 of them, the second channel has 4 reds, 24 4500k whites, 8 480 blues, and 12 410 violets.

[Timfish]

There are no easy answers to lighting partly because different corals are using different parts of the lighting spectrum. I would suggest starting by reading this article then others by Dana Riddle:http://www.advancedaquarist.com/2012/12/corals

One example of how complex and potentially confusing lighting can be is while we are repeatedly told about PAR and PUR one chromoprotien, CP 586, which gives many corals their purple coloration REFLECTS the blue and red spectrums that are measured by PAR meters and absorbs yellow light. Why would a coral get rid of light needed for photosynthesis and absorb light that is not needed for photosynthesis?

Both the LED combinations/ratios given above will very well but keep in mind no matter what you do there will be animals that do not like it. Even your initial combination with mostly NW and RB will work but I would at least use a combination of RB, B and UV/Violet. Your best success will be to match your lighting to the conditions the corals you are getting were grown under. I get 99% of all my corals locally where I can see the tank and talk to whoever grew it about the corals husbandry and history of the tank.