Wave Length, LED, and PAR

pelagic · Jun 29, 2011

Wavelength, LED, and PAR

LED is getting more popular in our region, Bill and I had a brief discussion about wave length needed for SPS and LED selection before the meeting last time.

Here's the list of links and notes I got when I built my light.

====PAR
Lighting In Reef Tanks: Some Actual Data
Feature Article: Lighting In Reef Tanks: Some Actual Data — Advanced Aquarist's Online Magazine

How Much Light?! Analyses of Selected Shallow Water Invertebrates' Light Requirements
Feature Article: How Much Light?! Analyses of Selected Shallow Water Invertebrates' Light Requirements — Advanced Aquarist's Online Magazine

MAX PAR for some SPS, it means the certain type doesn't absorb more than the amount of PAR.

Acropora cervicornis 281
Acropora cervicornis 331
Acropora digitifera 387
Acropora divaricata 77
Acropora formosa 340
Acropora gemmifera 340
Acropora granulosa 107
Acropora microphthalma 300
Acropora millepora (coenosarc) 190
Acropora millepora (polyp) 230
Acropora nobilis (coenosarc) 310
Acropora nobilis (polyp) 180
Anthopleura elegantissima (anemone) None @ 540
Cyphastrea serialia (coenosarc) 150
Cyphastrea serialia (polyp) 150
Montipora tuberculosa (coenosarc) 180
Montipora tuberculosa (polyp)
Pocillopora damicornis 225
Pocillopora eydouxi 323
Porites cylindrica 200
Stylophora pistillata 600-2000
Stylophora pistillata (shade) 200
Stylophora pistillata (light) 300

====Wave Length Needed for coral photosynthesis

The following Chart looks different than the PAR reader's Chart

The Par Reader Chart can be found at
Apogee Instruments Quantum Sensor - Spectral Response

chlorophyll f is a fairly new finding, I guess that's why Par meter didn't include it.
link: Chlorophyll F, a newly discovered photosynthetic pigment uses infrared light

====LED
Someone once told me, light is food to Coral, and the coral has different mouths for different food.

1.chlorophyll a(let's call it Chinese food mouth)
2. chlorophyll b(American maybe?)
3. Carotenoids(italian)
4. chlorophyll f(maybe)(Mexcican sounds good?)

The reason why MH is better is because it covers a wide range of wavelength. in the other word, it's like a international's market.. it feeds all the mouths of a coral.

The most commonly used Cree LEDs are XP-G and XP-E
their spectrum look like this

compare these 2 to the Wave Length Needed for coral photosynthesis chart, you can see corals like to eat from
1. XP-E Royal Blue
2. XP-E Blue
3. XP-G Cool White(5000-8300K)
4. XP-G Neutral White (3700-5000K)
5. XP-G Warm White. (2600-3700K), maybe not that much of this.

It's nice to mix 1, 2, 3, 4 in a light fixture, not saying you can't just use let say 1 and 3, but it will just be more efficient if you have more variates available. It just reduce the time needed for the coral to get full.

That's the conclusion of my note. any comments and questions are welcomed.

mixer911 · Jun 29, 2011

Nice Cheng!

mike_dani · Jun 29, 2011

Cheng, after reading you post I am once confused again on the section of LED's for my fixture.

My plan was to light up my 300 gallon SPS reef with LED's, I was going to use two high voltage drivers to power 136 leds consisting of 68 XR-E Royal Blue and 68 XP-G Cool Whites. I was going to use 34 leds per string alternating every two inchs from blue to white over a 72" span. Now when I look over you data it looks as if I will benefit by using 4 different color temps on each string. Would I need to add a XP-E Blue and a XP-G Neutral White to the build and alternate them like below?

Royal blue, then cool white, then blue, the neutral white separated every two inch's over a 68" span on 4 separate strings?

poolkeeper1 · Jun 29, 2011

This affirms the info that I have been told by ledlights and the only thing i would add is that there are new Led's that you did not mention, Like High Noon and a very high lumen 3 W Led that is coming out soon. Depending on who you listen to the Nuetral Whites and Warm whites are not needed but Reds can be added to the mix also for color pop.
You also do not mention what MA the Led is powered at has an effect on it's benefit to the living organism along with photoperiod length. You can run The high noon whites for only 4 hrs and get as much benefit as running Cool whites for double that if I understand it correctly. It all comes down to selection and time the Led's are run for what you have in your tank to be sucessful, I think?
Great collection of Info to compare things with though.
Bill

poolkeeper1 · Jun 29, 2011

mike_dani said:
Cheng, after reading you post I am once confused again on the section of LED's for my fixture.

My plan was to light up my 300 gallon SPS reef with LED's, I was going to use two high voltage drivers to power 136 leds consisting of 68 XR-E Royal Blue and 68 XP-G Cool Whites. I was going to use 34 leds per string alternating every two inchs from blue to white over a 72" span. Now when I look over you data it looks as if I will benefit by using 4 different color temps on each string. Would I need to add a XP-E Blue and a XP-G Neutral White to the build and alternate them like below?

Royal blue, then cool white, then blue, the neutral white separated every two inch's over a 68" span on 4 separate strings?

Not necessarily, You can add them for the Look you get but they are not needed for Photolysis's by the corals (According to ledlights) There are other Led's to consider though and I would talk to Bill or Rick @ ledlights as they know everything you are asking.
Bill

Troylee · Jun 29, 2011

Nice chart and specs man love it!!!! Why not share with everyone???? I smell a thread of the month...:tongue:

pelagic · Jun 30, 2011

Cree XP-E Blue vs Royal Blue, XP-G White VS. Neutral White

In My build I have 44 Royal Blue, 6 Blue, 16 Neutral White, and 9 Cool White.
Here's the reason why Royal Blue>Blue, and NW>CW

========Cree XP-E Blue VS Royal Blue

As you can see, Royal Blue covers a lot more area than Blue, some people get some blue instead of all royal blue for the look and to cover some other spectrum.

======== XP-G White VS. Neutral White

NW and CW cover almost the same amount of area from 400-500nm, but from 650-750nm, NW covers almost twice as much as CW, it also benefits some chlorophyii f.

Again, there's nothing wrong w/ just using CW, RB, it's just more efficient to mix more types of LED.

pelagic · Jun 30, 2011

poolkeeper1 said:
This affirms the info that I have been told by ledlights and the only thing i would add is that there are new Led's that you did not mention, Like High Noon and a very high lumen 3 W Led that is coming out soon. Depending on who you listen to the Nuetral Whites and Warm whites are not needed but Reds can be added to the mix also for color pop.
You also do not mention what MA the Led is powered at has an effect on it's benefit to the living organism along with photoperiod length. You can run The high noon whites for only 4 hrs and get as much benefit as running Cool whites for double that if I understand it correctly. It all comes down to selection and time the Led's are run for what you have in your tank to be sucessful, I think?
Great collection of Info to compare things with though.
Bill

One of the highest 3w lumen LEDs I know is XM-L, 260lm flux @ 700mA
Link:XM-L Cool White T5 | CREE LED

for the comparison purpose, percentage was used, instead of the actual lumen based on the current input. if you are interested in the lumen comparison, the spec can be found in the links above and cree's website.

An useful link here
Coral Photoacclimation by Andrew Trevor-Jones - Reefkeeping.com

When you give the coral enough "Food", they will get full, and they will start "vomiting" Zooxanthellae if you keep giving it more light.
So, if the light fixture has the right spectrum, then you can reduce the operation time for the light and make it more efficient.