Lets talk about ~Lighting~

[mojoreef]

Alrighty then lets break down Reef lighting. I think we will do this in two parts. First part is going to be how it works and how it gets done, this way we can get some knowledge behind us, that way when we breaking down lighting sources(second part) we have some back ground.


MIke

 

[esmith]

Great topic can't wait to hear more!

Eliyah

 

[mojoreef]

Corals have Zoox which is an algae, actually they are dinoflagellates. they are the same as the nasty ones in our tanks. With in this dino are pigments. A series of chlorophyll’s which are green and carotenoid peridinin which is yellow. (yellow and green make??? brown, thus most corals are brown) now these pigments are basically chemical molecules that possess the ability to absorb visible light photons. and so the process starts. The energy of the light photons are captured by these pigments and transfered through a sytem called ETS (electron transport system). and eventually end up in a reaction center, which leads to the formation of ATP and NADPH . ATP is the food (Hmm andrenlintriphosphate??? (sp). and nadph is reducing power. both form organic compounds the coral can use as food.
Now the ammounts of these pigments in corals is not a carved in sstone thing, they can have more chlorophyll’s and less carotenoid's or visa visa and this can influence the color of the coral and/or clam. So how does that influence the light we use??? most of the pigments chlorophyll have a strong ability to gather light in the blue and violet range. the other more dominant pigment carotenoid peridinin mostly absorbs blue light waves, but does absorb violet and a tiny bit of green. So you make the call on the K of the bulb you wish to use (or combination).
So now lets move away from the aglae that is providing food and take a look at some of the actual colors of the corals, because as we know not all corals are brown (thank God).
Also with in the coral are more pigments. they have a variety of different purposes and requirements. they reside with in the tissue of the coral itself. Now these pigments do not have the ability to traansfer light energy, but it has been found that in very deep waters they ave the ability to alter particular color wave lengths. This is done by absorbing one color and the fluorescing a color the coral can use. SPS or shallow water corals produce large ammounts of pigments under high lighting intencity. So lets get into the meat of it.
Most pigments in coral tissue are called pocilloporin and are catagorized as either Brightly Colored Low Fluorescent Pocilloporins or as Highly Fluorescent Pocilloporins. Highly Fluorescent Pocilloporin pigments have the ability to absorb light with a specific wavelength and then fluoresce or emit this light into a different wavelength. Most of the highly flouresent varity act as UV protectorants. protecting the coral and algae from UV's and to much light. the lower flourescent types tend to help the Zoox pgments convert uv and /or violet leght into something useable.
these pigments absorb light basically with in the zone of 400 to 620 nm. violet to blue to some green and some yellow and some red. they absorb those light but fluorese dofferent colors back out. the colors the fluorese out are the colors we see in oour tanks.
So conclution...sorta. most of the light waves corals use for growth are in the range of blue and violet. this is for food but not necessarly the color of the coral. the pigemnts inside the corals tissue, have a roader range of absorbtion and emit a different color then they absorb (usually). but it has nothing to do with thier feeding process.

Mike

 

[mattseattle]

great post. so then it seems clear to me that we as reefers need Actinic which is at 420nm in order to get proper coloring of our corals. Do actinics also contribute to good coral growth or is it more food production and pigmentation?

I just added Actinics VHO's to my tank yesterday and it's already made a difference in the coloring of my corals even when the lights are not on

 

[esmith]

~4months ago when I needed to replace my lights, instead of getting an actinic bulb (I am running 3 55 watt PC's over a 30g) I decided to get a 20,000K blue light which is rated at 420nm. I really like the coloration that it provides over the actinic, and it's much brighter.

My question would be, is this 20K light any different than running a straight actinic (other than being of a higher kelven rating)?
Should I still use an actinic, or is this doing the same job?


Eliyah

 

[mojoreef]

Matt/eliyah no we dont need actinic, or at least as we know it in the hobby. In the hobby we refer to actinic as vho or pc type lighting. The color range mentioned above relates to colors as they apply to wave lenghts. MH's will give the same color ranges as will most vho/pc's but at greater intencity. and intecity plays a large role.

Heres one to screw everyone up. In regards to intencity, an electron receptor on zoo needs a certain level of intecity in order to excite the electron into starting the process. This can happen as quickly as a flash from a camera. once that has happened, the process can continue and normal average lighting.

Mike

 

[Katchupoy]

IMO (although not based on any research)... I think we still need the blue side spectrum or actinic.

Why?

Everytime my MH (175w10k Ushio) opens up, my corals seems to shrink and not open up... and that will happen as long as the MH is open.... Compared to having just actinics during before and after of MH in which most of my corals do better.

Maybe, just in my case where almost are softies and very few SPS.

But whenever I changed it to AB bulb which is considered 14k spectrum... everybody is good....

Hmmmm..... what do you think....

 

[big t]

Wow my brain hurts a little now. Nice posts mike. I am very excited to be finally upgrading to my 250w halides when I get back in town this weekend. I am looking forward to seeing all those extra pigments mike was talking about show off a bit more.

 

[mattseattle]

well Jonas mentioned to me that we don't really need white light in our aquariums for coral growth/coloration and that the spectrum around 420 was the best. he said we just add white light in order for us to see.

so what is it?

 

[mojoreef]

Katchupoy I dont think you understood me, or maybe I didnt relay it well. Spectrum of light has nothing to do with actinics. Actinics is just a word we use for vho's or pc's. Lets dump the word actinics as it doesnt mean anything in regards to this. VHO/PC's will produce the same wavelengths as MH's its just the intencity that is different.

Mike

 

[NaH2O]

Great discussion!

For those interested: ATP = adenosine triphosphate & NADPH = nicotinamide adenine dinucleotide phosphate

Before we start to delve into the realm of bulbs....I was curious about some of the biological processes of the zooxanthellae. Ingrained in my brain is that SPS need stronger lighting than softies. So, is the zooxanthellae of SPS different than those present in softies? Or do they have a higher photosynthesis rate in comparison to softies (is it vice versa?)?

On the point of the electron receptor needing a certain "flash" of light intensity in order to start the process....how long would the process be able to carry on before it would need another "flash" to kick start again? Or is it the normal average lighting provides enough to keep the process continuing until the photoperiod would begin again?

 

[esmith]

Thanks for the clarification Mike...

Let me ask another question then, although I believe I may already know the answer, say I get a MH setup, would it be better to go with a bulb spectrum somewhere between 10 - 20K so that I get more light from the 400 > spectrum, or do the 10K's work best?

I think that I like a little bit of blue in my tank, I remember the photos I saw in the light bulb comparison on Reef Central and they 12K's - 14K's looked good. Some of the 10K's made the tank look totally washed out and bleached.

Bottom line, which lighting makes the corals and inhabitants happiest?

Eliyah

 

[NaH2O]

Eliyah, if I'm not mistaken, the K (Kelvin) isn't actually the light produced, but the color perceived. The bulbs would have to be measured in order to determine the actual spectrum.

 

[mattseattle]

Mike,
I guess you are right about when we refer to actinitics. I always assumed that when people talk about actinitics they are talking more about the Super Blue (420nm) bulbs than say the white. But I looked at different bulb descriptions for VHO & PC and they do use the word actinitics when they refer to both the white & blue spectrum.

Point noted for future reference.
----
Actinic White (12000K) = 50% actinic 03 blue phosphors & 50% white spectrum(triband). High performance upgrade which are great for corals, live rock, and related marine life.
Super Actinic R (420nm peak) = 100% blue spectrum. These are the most widely used aquarium bulbs on the market. They are great for reef applications and coral health.

 

[mattseattle]

I've read many posts on reefcentral where people say that corals grow best under Iwaskis 6.5k lights and color best under VHO Super Actinic (420nm). I see that many people use the 20k bulbs and have great coloring but not that great of growth. Is this just a urban myth or does corals grow best under one spectrum and color better under a different one? or do we mainly choose lights based on 'our' preference versus say the corals needs?

 

[esmith]

Nikki, thanks for clarifying that for me...I was not aware of that.

matt, I've actually read that natural sunlight is in the 5.5-6.5K so to mimick true conditions in the sea it would probably be true (although I wouldn't want the 6.5K's because they're way too yellow for my liking).

Eliyah

 

[mattseattle]

well I have 6.5k's 250w halides on my tank and with just those on it's too yellow for my personal view tastes as well. now that i've added Blue actinitics VHO's the coloring is perfect.

I've noticed since adding the 6.5k's that my corals are more extended and look alot better extension and growth wise than 10k's which I had on before.

 

[mojoreef]

Ok Eliyah. I am not going to tell ya yet, lol I want you to understand the process and how light energy works, because it plays a big role in both coloration and growth, which can be seperate from each other. If you read my first post it tells you at what color range corals zoox absorb the best, just match that up with a bulbs wavelength and you have a goodie. But remember color and growth are two different things.

Matt your getting the concept. the lower the Kelvin rating the more the intencity. Is all the light waveslengths used with and Iwasaki, no but its intencity of the waves it has makes up for it. will the color of the coral under a iwasaki be different then a coral under a 20K, yep. read the post again and you will see different pigments in the coral are excited by different light waves, that and they can absorb one color and flourese another. Hopefully how you choose your bulbs will be based on what you understand about the processes, hehe.

ok Nikki

Before we start to delve into the realm of bulbs....I was curious about some of the biological processes of the zooxanthellae. Ingrained in my brain is that SPS need stronger lighting than softies. So, is the zooxanthellae of SPS different than those present in softies? Or do they have a higher photosynthesis rate in comparison to softies (is it vice versa?)?

thier are different strains of zoox but they pretty much all act the same way. your question refers back to a previous talk about coral feeding. SPS type coral have evolved into using what is most plentyfull in thier enviroment. Corals require different things for diffferent operations. tissue is usually supplimented by outside food sources that contain N and P. SInce SPS have a very very thin veneer of tissue they can survive mere on thier zoox exclusively. Soft corals have evolved the same way but opposite, their enviroment is has a heck of alot more outside food and less light energy, thus they go that route. and thus they have a heck of alot more tissue.

On the point of the electron receptor needing a certain "flash" of light intensity in order to start the process....how long would the process be able to carry on before it would need another "flash" to kick start again? Or is it the normal average lighting provides enough to keep the process continuing until the photoperiod would begin again?

lol picture it this way on a natural reef thier is not just sun, they get alot of clouds and such to. the flash of intence light such as that from a glitter line thorugh the waves wakeup (excite) the receptors, once woken and in process the coral can continue the process on the average amount of light the sky has to offer. they dont start and stop every time a cloud passes by.
Now remember in this process and statement we are talking about growth.


Mike

 

[mattseattle]

so in essence it's probably the best bet to mix bulbs both for growth and both for coloration. because i can't imagine that there is one bulb that does it all. nothing is ever that simple

 

[jlehigh]

"imagine that there is one bulb that does it all. nothing is ever that simple "

hmm interesting idea matt! 4 bulb pendants alternating lights with the weather patterns synced up to the forcast or staying within the standard deviation of weather recorded in the almanac for the past say... 20 yrs!!

So we have talked about spectrum and intensity. What about POWER!!?? We know that as you move away from the light the intensity measured is reduced so those with tall/deep tanks go with higher output and generally MH since they pierce through the water the best. BUT, is there any reason other than depth that would drive a person to going with 400's over 250's or 1000 watt fixtures vs 400's! Industrial 1-5000 watt fixtures used for things like street lights and wherehouse lighting are much cheaper than our parred down 250watt fixtures and on top of that the energy efficiency tends to increase with the power as well... All this while still understanding that we cannot come close to matching the output of the sun... (I think)