Best Growth - Blue Light, White Light, or a Combination of the Two?

that Reef Guy · May 24, 2015

What gives the Best Growth?

All Blue Light
All White Light
A Combination of the Two (50/50 White to Blue Maybe).

I ask because in the Past I was Always Told

"White Light is Needed for Coral Health and Growth and Blue Light was for Visual"

"You cannot keep Coral Under All Blue Light"

"You need Full Spectrum Lighting (50/50 White Bulbs to Blue Bulbs)"

But Now people are Telling me the Opposite.

"Blue has Even More Photosynthetic Activity than the White"

"The Zoanthelae the Coral Host Utilize alot of Blue Light and Less with any other Part of the Light Spectrum"

"Yes, Blue is what is Needed for Coral Growth. White is Added for Visual"

So Which is it?

Please take Part in My Poll.

And Please Post Why you Voted the Way You Did.

Thanks in Advance.

Waters · May 24, 2015

I am with you.....I remember when I first started the hobby, it was more whites. Now everything you read states that the coral require the blues. That being said, I have seen successful reef tanks running nothing but blues; I have never seen a reef tank running all whites (with 0 blues). There should be an option for 80% blues and 20% whites

glb · May 24, 2015

Waters said:
I am with you.....I remember when I first started the hobby, it was more whites. Now everything you read states that the coral require the blues. That being said, I have seen successful reef tanks running nothing but blues; I have never seen a reef tank running all whites (with 0 blues). There should be an option for 80% blues and 20% whites

glb · May 24, 2015

I say both.

ReefTankRebel · May 24, 2015

I run my actinics and leds in the for the first hour then they go off and halide comes on runs 6 or so hours then back to actinics , led. I believe coral grows and thrives best under light that replicates the sun. That would be 6500k. But since most don't like that yellow look 10k light looks nice, a nice white. SO run those daylights lol then you get to look forward to that led look, like a treat at the end of the day.

nickg · May 24, 2015

I agree with ... I am a halide guy... I ran them for years with great results! I tried a little comparison, I purchased dimmable black box LEDs, 8 bulb T5, and new T5 bulbs and halide bulbs... I replaced my Halide bulbs. Waited 5 months and took Picts... The I swapped to T5's with all new bulbs. Waited 5 months and took Picts. Then went LEDs. Oh yeah, bulb temps, halides where 2 14K Phoenix and 1 20K Radium. T5's were all ATI mixture of colors. LEDs were 2 full spectrum dimmable and 2 50/50 dimmable... T5 had the best growth for me. I just hate the lack of shimmer!!! LEDs had the most pop. But had the lowest growth and caused something I never had with the others, insane algae!! Halides are just the best choice for me... I am currently working on a large upgrade.... It will be all 3, but not cheap black boxes!!! I put one on another setup, and bammm, algae strikes....

But natural light temperatures will give the best growth. 6500-1400K.

This is just my $.02

jeffp1 · May 24, 2015

80% Blues and 20% Whites for me with LED's. Lot better growth than with VHO's I ran previously.

sprinklerdudes · May 24, 2015

I have one tank I ran nothing but two t-5 fixtures 0ne46" 5 bulb fixture with 3- 6500k bulbs and 2- 10,000k bulbs and one 2 bulb fixture with antics amazing growth the other tank my t-5 fixture ballast went out, I switched over to led, loved the affect, but I did notice I was cleaning the glass a lot more, then I noticed a little decline in the tank, and a lot more red algae on the rocks. I love the led fixtures, and I think as they get better people will solve this problem with different arrangements of the leds and the intensity. Led is the future of the aquarium, I am just not real happy with the fixture I have. and probably going to purchase a new t-5 fixture, then in the next couple of years try another led. just my observations.

Reefing Madness · May 24, 2015

I believe they've found that in the 14-15k range people saw the best growth out of their corals.
http://successfulreefkeeping.com/learn/reef-tank-101/lighting-101/
http://blog.marinedepot.com/2014/08/reef-aquarium-light-color-guide.html
http://www.americanaquariumproducts.com/Aquarium_Lighting.html

hart24601 · May 24, 2015

I might have replied on another site - can't remember. I generally don't answer questions that are posted across sites since I am not smart enough to keep them straight, but anyway..

Like many things there really isn't going to be a definitive best. Despite our desire to categorize things into neat categories the real issue is much more complex. Short answer is use what you like - most lighting issues are for reefers to argue about!!

In reality how do you compare lights equally? Just use wattage? 10k vs 20k bulb? What about build quality of the bulbs or does a particular bulb need a special reflector or equipment? For LEDs the same issue applies - what blue vs white brand/current/bin?

So get past that and say lets just look at PAR on the coral. Well blue is better used for photosynthesis (more efficient) so the same PAR blue is much stronger than white or say green which is really poor. But now we are talking about the individual coral and light intensity. Coral can get too much light and hit photo-inhibition - the extra light is converted to heat which is dissipated by the water so a ton of flow helps with over illumination. So the water flow matter too. Anyway let's say we are looking at monti cap in 300 PAR over 12 hours of blue vs white light. At this level the blue could very well be too much for that coral and slow growth while the white level does not hit photo inhibition and grows faster because it's less efficient. Swap that cap with a shallow water acro and the blue might make it grow faster as it can use more of the light and not be over illuminated - but increase that 300 par to 700 over 12 hours and you might see the white grow faster due to the reasons above.

So it's hard to just say something like ______ grows coral better. Depending on the coral species or variety, with a set amount of flow, and the same photoperiod you might see some improvement, but modifying any of those conditions changes everything.

Now coloration is another thing. And feeding the coral appropriately sized food makes such a huge difference in growth that ime spectrum is not significant when looking at growth.

KoleTang · May 24, 2015

It's not just white and blue. There are many more colors that are used by zooxanthelae. Some of these colors are found inside white or blue, but depending on the particular source of light there will be a different mix of color. For example, Aquablue has a completely different spectrum than Geisemann Pure Actinic.

Read this: http://www.advancedaquarist.com/2012/10/aafeature

maroun.c · May 24, 2015

The old white for growth blue for coloration statement was true with MH lighting most probably cause even a bright white 10k bulb was still a full spectrum (partial red blue green blue...) so corals would not starve for any spectrum under a very white bulb. With nowadays LED even a mix of white and blue is not enough and vendors resorted to adding amber green and red... This is due to LED volors being pure white blue... So basically corals will starve for any missing light colors.
Keep in mind many other factors will affect growth and coloration like parameters and nutrients.the switch to LED took place roughly aroundvthe same timemost people switched to running low nutrient tanks which typically ran lower Alk which could have been responsible for slow growth (not to defend LeD) experiments with both lighting on same tank and different lighting.

Harold Green · Jun 27, 2015

I had good coral growth in the 44 pictured with a combination of cree rb and cw leds.

Joseph Jamal · Dec 7, 2018

If 50/50. What intensity do you guys run? %100? On less?

Scrubber_steve · Dec 7, 2018

Surely it depends on the depth at which the coral lives

Graffiti Spot · Dec 7, 2018

But really what percentage of corals are collected at that low depth? Low enough to where the light is changed is what I am talking about. Probably very very few right?

Scrubber_steve · Dec 7, 2018

There are many variables. Shading, for many hours per day - indirect light spectrum from this. The shimmer effect from surface agitation in some areas & not others. Turbidity. @Dana Riddle input would be enlightening

User1 · Dec 7, 2018

I think with the evolution of lighting this question will start to get answered a bit better with supporting data. The thing with LED's is the form fitting factor and adjust ability of both spectrum and intensity. Mix in some studies say by Ecotech / coral labs papers and others we can start to see what is working with actual information.

While I don't know what the percentage of captive vs. hobby propagated corals is I think the one link is understanding the source of the coral, its requirements, and if you can somewhat replicate it at home for long term keep. Then we can apply the proper light and spectrum. Today I think those using LED's are taking a SWAG at it and going by their eye sight for looks. Not that it is a bad way to start but back to my evolution of lighting point more affordable tools are coming along with data to help us better choose and then tweak for our eyes.

Edit: Then there are those who study or have studied corals and light that share information and try to make it easy to understand and tie to our lighting.

jda · Dec 7, 2018

This totally depends on the type of light. A blue MH will have tons of the other spectrums as well, it just looks blue to our eyes. A white MH bulb will have tons of blue. T5 do this to a lesser degree. LED really are a new phenonomen where they do not cover the whole spectrum.

You really need to understand the nuance of each type to understand how to answer this question.

The answer is simple... daylight for best growth (6500k spectrum)... then blue-it-up to your liking to illuminate. For LED, you need a mix of diodes to do this probably with different programs at different times of the day (the people who have massive success that run 100% on all channels all the time can stick with one program). With T5, a few tubes will do. With MH, a single bulb can do both.