LED Colors?

[jimsflies]

I noticed my DIY LED fixture I bought a couple years ago has two blue LEDs that are not lighting any more. Hard to say why it is, but I can't complain about a <$10 maintenance cost in a two year period.

So while looking into replacements, I am started thinking about adding a few more LEDs. I'm currently running 8 blues and 8 whites off two Meanwell 60-48D drivers. I believe these should be able to handle 12 LEDs each...and in fact may be on the low range of what they should be driving right now.

So what I am wondering is if I should just add more blues/white or if I would gain anything by adding red, green or violet into the mix?

I'm also not 100% sure, but I think the blues I have are "blue" not "royal blue", which as I understand it royal blue is a better LED for corals?

It might be worthwhile to add, that I tend to like the bluer look and my Apex currently runs the blues at 85%, but the whites only ramp up to 12%. I doubt this is an ideal way to run them...maybe I should go ahead and add a few more blues into the same driver as the whites so I can balance the load better? Or perhaps I would gain by swapping out the old white LEDs with a better binned current model white that would be a cooler white...the ones I have now look pretty yellow to me.

[dputt88]

having small amount of red and violet can be beneficial, green i find to be less important.

[Rabidgoose]

That's quite a few blues I think. I would replace some of those with royal blues and add violets. I am only referencing from the kit I just got. While their is some benefit with violet, red and green it is my understanding that it is mostly aesthetic. You also may need to tune your driver if you're adding LED's. (not sure)

chuck

[jimsflies]

I'm not sure about red. I've been reading some articles and here are some of the things they are saying...

The more red light a lamp generates correlates fairly well with low growth rates. (http://www.advancedaquarist.com/2008/12/aafeature1#section-5)

and here too...

These scientists used natural sunlight and filters to transmit a broad red bandwidth (~600 to 800 nm). (Note: Coral bleaching has also been seen at a narrower red bandwidth produced by an artificial light source - a light-emitting diode (LED) (http://www.advancedaquarist.com/2004/6/aafeature)

[Poseidon]

LED tech seems to be changing faster than Michigan weather. I have read that violet and cyan are the way to go now, with royal blue and "neutral white". I'd give a call to a couple different LED DIY shops and see what they have to say.

[pinhigh1886]

Jim I have the AI Vega Color and wish I got just the AI Vega Blue. The Green and Red lights are only on a few pucks and it puts RED/GREEN/PURPLE spots in (2) places in my tank. I turned them down to 5% also because it caused a disco effect in my tank. JMO. I am getting a few Brown patches on my sand bed that goes away at night too. I am running my Blues at 95% and White at 20% because i like the blue look as well. I am playing with the lights to see what is causing the brown bloom during the day. I heard that Red and Green can promote algae growth? Phos and Nitrites at 0 so I am thinking lighting is the cause. I am running the lights in Easy mode and they start at 9:30 AM and go off at 9:00 PM with a 1:45 ramp up and down. I also have 1% Royal Blue all night for moon light. May be just too much light.

[jimsflies]

LED tech seems to be changing faster than Michigan weather. I have read that violet and cyan are the way to go now, with royal blue and "neutral white". I'd give a call to a couple different LED DIY shops and see what they have to say.

I agree the availability and efficiency is changing. I guess the big question is what should we be trying to achieve with our lights? I'm not sure if its worthwhile to have red or not. Below is a graph that shows the absorption spectrum of chlorophyll. This graphs seems to show that red wave lengths are utilized by chlorophyll:

http://orphek.com/led/wp-content/uploads/2012/03/chlorophyll-a-+b.jpg

But the concern I have is looking at this chart in comparison to the information presented in the articles I linked to in my previous post seems to be contradictive. There is a big spike near the red spectrum indicating it should be beneficial to have them in a LED array, but the experiments show bleaching with corals exposed to red LEDs.

I'm not sure how they measure the information in the graph above, but there must be something else to consider with corals in the red spectrum. Perhaps corals can't handle the red spectrum as well being that it is one of the colors that are absorbed in the first few meters below the water surface.

http://www.seos-project.eu/modules/oceancolour/images/light_spectral_absorption_water.jpg


Jim I have the AI Vega Color and wish I got just the AI Vega Blue. The Green and Red lights are only on a few pucks and it puts RED/GREEN/PURPLE spots in (2) places in my tank. I turned them down to 5% also because it caused a disco effect in my tank. JMO. I am getting a few Brown patches on my sand bed that goes away at night too. I am running my Blues at 95% and White at 20% because i like the blue look as well. I am playing with the lights to see what is causing the brown bloom during the day. I heard that Red and Green can promote algae growth? Phos and Nitrites at 0 so I am thinking lighting is the cause. I am running the lights in Easy mode and they start at 9:30 AM and go off at 9:00 PM with a 1:45 ramp up and down. I also have 1% Royal Blue all night for moon light. May be just too much light.

I am also concerned about the disco effect. I don't have any coral that I want to spotlight with a different color. So blending the colors so it looks good is a primary objective.

Regarding your brown patch issue, I suspect it is diatoms or cyano. Both are photosythetic, it may be possible that they respond differently to different wavelengths of light. I guess it would be interesting to see if it resolves by adjusting color output of your Vega. You'd have to try different scenarios to see if you could narrow it down to a particular light wave length of light.

[Poseidon]

Jim, the studies that I saw regarding red LED's were conducted using exclusively red correct? That is not what the average fixture does.

Oh, I found a REALLY simple solution to help with the disco effect, I placed pieces of "scotch tape" over the reflectors of the red and green, the frosted tape helps to disperse the color over a greater area, reducing the spotlight effect. Eventually manufacturers are going to start putting different optics on these colors, I am surprised it has taken this long.

[pinhigh1886]

Yeah I agree Jim. I have had the Vega now for about two months. I used t5 prior ATI bulbs. No algae at all not one bit. Switched to AI and ramped up over a month for coral acclimation. I wish I was watching the algae at that point but really didn't notice until I was ramped up fully. I turned red completely off tonight. I will let that go for a few days to a week and document change. Then try green. Then reduce intensity and over the next few months see what happens with the brown areas. I am pretty sure it is diatom bloom not cyano. It really does not have any thickness to it. It is just like a thin dis coloring.

I plan on designing my own pucks once AI makes them available. I also only have 2 fixtures and I think I need a third on my standard 90 gallon

[Rabidgoose]

I was advised to use "warm whites" (no optics) instead of green or red.

[ReefTech]

I was wondering if anyone with a DIY fixture has ever run it with just the optics over the blue LEDs and not the whites? I found that when I had mine above my frag tank (48x18x12) that not having optics on the whites meant I could turn up the intensity on them without bleaching or discoloring any of my acros. The fixture was hung 5" above the tank and its only a 24" fixture so I know it's technically to small for the tank. The fixture has 40 Cree LEDs and I can dial the intensity of the blues and whites to whatever I want them to be. I'm experimenting right now and hung the fixture above my 120 without any optics on it and just let it run one of its pre programmed light cycles and again all the acros look great with great polyp extension. Haven't noticed any of them losing color and turning brown yet but the tank is 24" deep. So this is why I'm wondering if I should put the 90 degree optics back on the blue LEDs only just to make them more Intense and get more penetrations I the bottom of the tank. So if anyone has tried this before or has any ideas please let me know.

[jimsflies]

I'm not running optics on any of mine. But I would tend to think that the blue leds pack more of a punch than whites in terms of energy that corals use. Its interesting that whites caused corals to bleach.

I'm frankly still a bit unclear on white LEDs anyways...as I understand it they are simply blues with a phosphorus coating making it look white. If light looks white, does that mean its white? White light technically have all the color spectrum, right?

It seems like one has to be a quantum physicists with a masters in biology to put all of this information together into something that makes sense.

[ReefTech]

Yes, true "white" light is composed of the entire light spectrum ROYGBIV. Red,orange,yellow,green,blue,indigo,and violet. That's why white LEDs are measured in Kelvins and not nanometers. The kelvin rating if a white led tells you what part of the spectrum it focuses more on but it still gives out the entire spectrum. That's why some of them give off what seems to be the dreaded yellow effect and others will almost of a hint of blue in them. Same thing as halide bulbs. Those are so successful because they create and give of true white light, unlike most white LEDs which are in fact coated with phosphorus to give the white appearance. So if I have my facts straight I think the problem of the white LEDs is that the actual temperature of the led itself will cause a shift in the spectrum it's giving off. So if you run your whites at a higher intensity, over time that led is going to hear up, hence why we mount them on heat sinks and some units have fans. And when it heats up I believe it gifts the spectrum some what and if your running optics on them then that's why sometimes you can get browning or bleaching of your corals because the spectrum shifted to probably somewhere between blue andgreen or orange on the spectrum which that chart that Jim posted clearly showed that chloroform a And b can't absorb energy from the light in those spectrums. So you are pretty much hitting your corals with intense beams of light in the wrong spectrum that it needs and I have found that will cause the browning of acros and occasional bleaching as well. But again I'm in no way a physicist so I'm just going off research I've done and people that I've talked to.