My Overall Theory of Light (Information heavy)

[Andrew17030]

Use metal halides or T5's or both and not too bright, got it.

 

[teknik777]

What bulbs would you suggest for a sps dom tank with 250 mh and 4 t5's? Great write up btw!

 

[ReeferBatman]

I'm not sure, check their measured PAR.

I would assume if your MH has your upper registers nm covered, then you could supplement optional T5 with more blue bulbs to "accent" the lighting...

unless the corals in question can use more Intensity of those upper nm registers... in which case throwing a 10k [or other]T5 on would help growth...

The trick is to balance nm of corals need with intensity of that light [not too much].

 

[Lionfish666]

Good write up, knowledge is to be shared and evaluated, whether or not you performed the experiments or wrote the paper.
It certainly wasn't a personal attack on people with LED and niggling over the correct scientific terminology after such an effort has been made for all comes across petty and counterproductive.
The whole point of forums is to share your opinion, if you want original science go do the below experiment yourself and share the results with us -
I would like to see one four foot tank split into sections with black perspecs (water shared through slot at the bottom) with one standard LED section, one MH, one t5 and one custom LED rig with equal par values. Place a stargrass and monti frags in each section, all same size, split at the same time from the same parent and observing the colour and growth after 1 month intervals.
Regarding the above information, I think the limited output of LEDs mentioned is very much exaggerated by the fact a single bulbs was used as a measure. No one would use just blue on their tank. Still there is truth to the argument that LED doesn't emit the UV spectrum evenly, the stock standard cool white/royal blue combination, is obviously lacking in the overall spectrum, missing UV completely and an unrealistic dip in the reds, oranges and yellows compared to sunlight.
My somewhat ignorant understanding is that if you combine neutral or warm whites with blue and royal blue plus some UV for the lower end of the spectrum is that with LED alone you can effectively cover the whole spectrum. Well, hopefully this is true as this is what I have after my research.
Note - I am bias towards LED. Everyone has bias, whether they admit or not that's their bias. It's human nature. You can't draw conclusions or even understand information without your brain interpreting it in a way it understands, which is based on previous understanding and brain chemistry. Sharing is caring, whether or not you agree.
But hey that's just my opinion, I'm no scientist, but at least I'm not a troll.

 

[shrimphead]

"Chlorophyll synthesis is the chemical reactions and pathways by the plant hormone cytokinin soon after exposure to the correct Nanometers wave length (about 670 NM) of light resulting in the formation of chlorophyll, resulting in continued growth of a plant, algae, zooxanthellae and the ability to "feed" and propagate, and without this aspect PAR (670 NM light energy), zooxanthellae and plants cannot properly "feed" propagate. The results of the lack of this high PAR "spike" would be stunted freshwater plant growth, and eventually poor coral health in reef tanks.""

can you give a reference to where you heard this bit I read that when different corals where tried to grow in different coloured lights (blue, green, red) blue light grew the corals best. also like you mentioned that the red light is filtered out the deeper you go so alot of corals aren't even going to get that(670) wavelength

 

[ReeferBatman]

"Chlorophyll synthesis is the chemical reactions and pathways by the plant hormone cytokinin soon after exposure to the correct Nanometers wave length (about 670 NM) of light resulting in the formation of chlorophyll, resulting in continued growth of a plant, algae, zooxanthellae and the ability to "feed" and propagate, and without this aspect PAR (670 NM light energy), zooxanthellae and plants cannot properly "feed" propagate. The results of the lack of this high PAR "spike" would be stunted freshwater plant growth, and eventually poor coral health in reef tanks.""

can you give a reference to where you heard this bit I read that when different corals where tried to grow in different coloured lights (blue, green, red) blue light grew the corals best. also like you mentioned that the red light is filtered out the deeper you go so alot of corals aren't even going to get that(670) wavelength

Few things here...

1) Chlorophyll containing cells are one of the more "productive" phtotosynthetic cells. They produce a lot of food for the organism, and are preferred. Plants and Corals that have access to higher nm peaks can utilize chlorophyll. But chlorophyll does need both spikes in the Lower AND upper nm registers.

If the organism receives only the upper nm / red spectrum, it can't fully use photosynthesis via chlorophyll.

Add to that, there are two types... Chlorophyll A and B...
A is more productive in food given to the coral,
but B requires a lower nm peak for full activation, and is slanted more heavily toward the blue end of the spectrum.
It follows logically then, that most of our corals that do use Chlorophyll rely more upon Chlorophyll B.

2) Many corals evolved lower on the reef and therefore had access to less par at depths. And as we have seen [via links and pics above] there are a multitude of different photosynthetic cells that each use their own particular nm spectrum. And the majority of these lay between 400-600nm (often giving us the awesome coloration of Greens, yellows/oranges we are familiar with).

So corals that [grow deeper on the reef and] contain those particular [blue-green light] strains of photosynthetic cells have grown over time [via natural selection] to rely more upon these "blue/green" cells than "chlorophyll cells"... the coral had to because it couldn't get that extra red 'spike' chlorophyll needed.

This is why we see increased growth of corals under experiments pitting ONLY blue light vs ONLY green light vs ONLY red light, etc...

Some photosynthetic cells can still produce food for the organism with ONLY bluer light...

However very few photosynthetic strains in corals rely upon nm higher than 600 (red) with the exception of Chlorophyll, which again needs BOTH Blue AND Red to produce food for the coral...


All these studies of red only vs blue only merely go to prove what we already know...

Corals do rely more on blue light than red light relative to each other for photosynthetic food production.

That said, even though corals rely more on green/blue light than yellow/orange/red - there are still many photosynthetic strains (and the resulting colors we see given off by the coral) that are likely contained within the coral that would use that yellow/orange/red light up to and over 600 nm.

Most corals have at least a few different photosynthetic strains in them... if the light was available to you, and you could make food from it, why wouldn't you?

IE.

Some corals can survive under bluer light only... and may even be damaged by the intensity of even small increases in nm PAR offered...

But most corals would thrive better (and have better coloration) if they were offered light in the higher 500-600 nm PAR as well.

Example...

I didn't see a Yellow band on my Prizm Favia until I doubled the amount of 10k T5 light I was giving it... even though green coloration stayed just as prominent.

The Favia had many strains of photosynthetic cells, and while it was surviving and growing under "more blue light" just fine, those particular "yellow" photosynthetic cells were effectively inactive (not producing color for me or much food for the coral) until it received its required intensity of it's "activation spectrum" of nm.





If you have to go for "only blue" or "only red" light, you'd be better off going for "only blue". However, your coral would thrive and color up better if offered a wider range of color nm in addition.




Once you get the right balance for your needs, you can still add additional blue lights to change the "Kelvin color" overall appearance of your tank for aesthetics ... as long as you don't increase the intensity to where it would hurt the coral.

 

[Wannabe29]

There is nothing ambiguous about "many sources". He is not claiming this is his own work, but rather states plainly that is a compilation of other works.

Ok...first off, I found the information presented to be interesting, though nothing new in terms of ideas about LED lighting vs. other forms of lighting used in this hobby.

That being said....and this really has nothing to do with the scope of what was discussed....when using outside data/sources as evidence for a thesis, it is important to cite your sources. When writing a thesis, you are doing so based on an idea/observation that you have and want to discuss. Because of that, you need to cite your sources to differentiate to the reader what ideas are yours and what you are taking from someone else.

Further, it is important that a reader be able to "check your sources." I'm sure we've all heard that phrase before. You could be getting your information on light spectra and evolutionary phylogeny from Joe Schmoe's Journal of Juggling and General Clown Entertainment Arts. Whlie JSJJGCEA might be a respected journal among all circus performers, a paper written citing the Journal of Evolutionary Biology is going carry more weight when discussing issues about evolution and biology.

However, this is not a formal peer-reviewed article or a college research paper, so I think we can let him slide on this particular issue.

 

[reeferstace]

When a photosynthetic organism (in this case the mutualistic symbiotic unicellular algae of the coral) absorbs a particular wavelength of the visible light spectrum, it converts that light energy to chemical energy that is stored in the bonds of carbohydrates. The colors you see when you look at a coral represent portions of the visible light spectrum that are reflected by the organism. Reflected light CANNOT be harvested for carbohydrate production. The color a coral looks has nothing to do with the portion of the spectrum they are using.


Also, you are keep speaking of chlorophyll as if it's the only photosynthetic pigment (NOT strain). There are many others. In fact, major algae phyla are classified by their photosynthtic pigment contents. Symbiodinium, which is the genus of zooxanthellae symbiont typically found in corals, mostly use chlorophyll c and fucoxanthin. They have a myriad of other pigments that are used to capture light energy as well.

 

[ReeferBatman]

Also, you are keep speaking of chlorophyll as if it's the only photosynthetic pigment (NOT strain). There are many others.

If you read the first post you would see I covered that, and gave lists and links to more detailed lists on many many different pigments or "strains" of "photosynthetic cell".

The colors you see when you look at a coral represent portions of the visible light spectrum that are reflected by the organism.

The coral throws up ‘deflectors’ to get rid of light it doesn’t need, and this is the light we see emitted.

The color a coral looks has nothing to do with the portion of the spectrum they are using.

Although the nm spectrum absorbed does not always define the color emitted from the coral, there are very often correlations especially in the fluorescing pigments which we coral lovers are so fond of. See pics and links on first page. Many of the "strains" emit light within 30nm of that which it absorbs [many within 10-15 nm]. very few are much over 70-90nm different. That allows us to make some generalizations when speaking of fluorescing pigments.

But, there are also non-fluorescent "strains" that absorb green light and throw off yellow, etc etc - you are correct.


Corals will use whatever "strain" or pigment they have at their disposal... Some corals can still use chlorophyll A...

http://www.biolbull.org/content/135/1/141.short


http://www.int-res.com/abstracts/meps/v191/p53-69/

http://www.springerlink.com/content/uq41yw8hj481cxcl/

 

[ReeferBatman]

Back on the Chlorophyll note... maybe we should talk about Chlorophyll D which tends to be used in red bacteria and cyano blooms... This is why people say "stay away from the Red light...it causes bad algae blooms"...

http://www.biology-online.org/dictionary/Chlorophyll_d



On a separate note... an interesting link I came across..

http://rspb.royalsocietypublishing.org/content/236/1284/311.short

The increase in zooxanthellae numbers was linearly proportional to the increase in protein in zooxanthellae, suggesting that availability of inorganic nitrogen leads to increased protein synthesis in zooxanthellae.