Red as a supplement for LED builds

[reefdummy]

So I cant sleep so I just got thinking about an LED built I might try, and I subsequently started to think about that whole color issue we're getting from the using the current 'standard' (ie. RB & CW)

 

Another member on different thread (clintax I believe) started talking about how the corals fluorescent proteins take in one wavelength (ie color) and emit a different one. This got me thinking about how exactly this pertains to red and 'red-like' corals--some of the most effected by this current lighting scheme.

 

According to this paper (I believe it's just a review of red florescent protein [rfp]--the protein that fluoresces red in the coral), rfp takes in 555 nm and emits 585 nm. Those numbers correspond to the protein absorbing a color somewhere between yellow-->green and emitting a technically orangish color [color wavelength definition]--which in reality looks quite red as you can see in the paper

 

So--what does this mean? Perhaps red is int actually doing anything; in terms of fluorescence--making things 'pop'. You would only get that 'red-pop' from warm whites

 

 

This is from the cree xre series spec sheet (one of the most common LEDs used in buids). If you look at the first graph, the Green and Red lines represent the spectrum's of neutral white and warm white, respectively [NW and WW color temp]. These have a significantly higher 555 nm maximum than cool whites--which is according to the above is the color spectrum needed to make red florescence.

 

Meaning that cool white wont make the reds pop as much as the neutral and warm whites.

 

Unfortunately this data sheet is leaving out some of the other LED colors' dominant wavelengths--it only has RB, B, and G. If the specs for colors like cyan and red were available it would be easy to tell if these would actually increase fluorescence

 

Also something to note, it may not actually be rfp (red fluorescent protein) that is the source the red coloration. A non-florescent pigment could be the real source of the red we tend to lose in current LED builds, meaning that indeed it is just the actual wavelength of red that is missing. However, I feel that red 'pop' can only be caused by florescence

 

I know this doesnt mean jack compared to actually doing it and seeing results, I just thought it was interesting to think about

 

I hope someone actually reads this lol Im feelin a lot of tl;dr

[ApiratenamedJohn]

Pretty interesting. So if I'm taking this in correctly, having a little bit of everything is the best as far as an led build would go?

[reefdummy]

Pretty interesting. So if I'm taking this in correctly, having a little bit of everything is the best as far as an led build would go?

Kind of. Im trying to show that in order to get red pop you shouldnt give the corals red--you should give WW or NW because these emit a wavelength the corals can process into red (and CW has very little of this wavelength)

[SWAG]

interesting

[lizardfish]

sweet info! thanks, i have been looking into thiss as well. i see one problem with NW leds.. there is a ton of yellow, most of us dont like the yellow tint and add more RB giving a to purple look. so what about adding green leds in the mix? or use high bin cree's 8000K or 10k bridglux with green and red leds?

[evilc66]

One reason that we have avoided using discrete red LEDs is the effect they produce on the tank. With the right (wrong?) setup, they can be very distracting, and not blend well with the tank. Plus, it's just another color that has to be controlled and spread over the LED array. Going to a warmer white LED adds color in ways that direct color LEDs cannot. The phosphor lays out a much broader spectrum over the areas that you want (red and red-orange), but does also create light in areas that you don't. The effect will be different.

 

It's the same reason we don't use RGB LEDs to create white light. The eye thinks it looks ok, but unless the object under the light has colors that fall on the dominant wavelengths of the LEDs, the colors are going to look muddy and crappy.

[AnthonyPf]

evil you are correct about easily over powering the tank with red. That is why you have to be sparing with it. Now that some LEDs are very efficiently generating 660nm it seems like a no brainer to add a little red. It has been documented in many places that corals photosynthesize at this spectrum.

 

I can not tell you how happy I am with my single red 660nm LED. The acceleration in growth is noticeable after a very short time.

[reefdummy]

I see one problem with NW leds.. there is a ton of yellow, most of us dont like the yellow tint and add more RB giving a to purple look. so what about adding green leds in the mix? or use high bin cree's 8000K or 10k bridglux with green and red leds?

I cant speak for the aesthetics of NW concerning the yellow, but CW has significantly less in that spectrum. I would think that if you were to mix NW and CW in some ratio you could still get the red-boosting effects of NW but make sure there isnt too much yellow with the CW.

 

This is just common sense though

 

Like Evil says below, there are problems concerning mixing in single colors. If you look at the cree spectrum sheet the greens have their peak right where the NW and WWs have theirs--so I think green would only exacerbate the problem. I dont know anything about cree 8000K or 10000k

 

One reason that we have avoided using discrete red LEDs is the effect they produce on the tank. With the right (wrong?) setup, they can be very distracting, and not blend well with the tank. Plus, it's just another color that has to be controlled and spread over the LED array. Going to a warmer white LED adds color in ways that direct color LEDs cannot. The phosphor lays out a much broader spectrum over the areas that you want (red and red-orange), but does also create light in areas that you don't. The effect will be different.

Absolutely true. There are ways around these color blending problems though with diffusers, close placement, etc. I just wrote this up to show that adding Red LEDs should not make red corals show their colors. Neutral white is the way to go

 

Now that some LEDs are very efficiently generating 660nm it seems like a no brainer to add a little red. It has been documented in many places that corals photosynthesize at this spectrum.

 

I can not tell you how happy I am with my single red 660nm LED. The acceleration in growth is noticeable after a very short time.

I wrote this up just concerning the loss of red colored corals and how to correct it, but the photosynthesis (PAR) aspect of this is also interesting.

 

I found this paper which analyzed all of the protein/chlorophyll complexes in dinoflagellates (zooxanthellae) and their active wavelengths. I overlayed the complex that had the broadest spanning absorption spectrum onto the above graph so we can compare what these LEDs are actually doing in terms of powering these complexes.

 

 

WW and NW both contribute a significant amount (~35-40% relative amount) to the smaller secondary peak in the chlorophyll complex (~672 nm). Obviously 40% could be boosted higher for higher absorption and thus more coral growth.

 

660 nm definitely falls into this secondary peak, but the sweet spot would be 670 nm.

 

At the other end of the spectrum, you can see WW has a much smaller peak near the major peak (~438 nm) than either CW or NW.

 

Interestingly, all of the whites' spectrums quickly fall off below ~440 nm and dont contribute a significant portion to that part of the major peak. Adding these new 420 true violet LEDs would be much more beneficial to the coral than adding red, since the chlorophyll is more than 2x as absorptive at this spectrum (~100% vs ~40% relatively). It appears that white LEDs are also lacking the in the ~480 nm range as well.

 

Like I said above though, all of this doesnt mean anything until it is practically applied. I just think it's interesting to consider things like this.

 

~~~~~

the super TL;DR

 

Neutral white is the way to go--in terms of red color resolution and boosting coral growth when compared to WW or CW. However, just NWs will look like crap due to the huge amounts of yellow in the spectrum, so some CW or other LEDs are necessary to keep the relative yellow down.

 

Red LEDs should help with PAR but will do little to made red corals look the way they are supposed to. True Violet LEDs should be even more effective though at boosting some of the lost PAR (compared to just blue and white LEDs).

 

Again, this is all just food for thought and the actual application of of color mixing/balancing may be more of an art than a science