Lighting conversation

[mojoreef]

Anthony in a previous post we briefly talked about artifical lighting we provide for our tanks and how it interacts with our corals. I would like to take it another step if you got some time.

In the wild SPS type corals get about 95 to 98% of thier energy budget through photosythisis and need to suppliment the balance. In reading your previous post you are saying that our artifical lighting does not meet the same intencity/per and so on, thus the ammount of light given to our corals is somewhat less then what they would recieve in the wild. Because of this the amount of food taken in through photo has affectively been reduce to a number below that of the wild. Not sure what it would be but less.
The statement made some sence to me, so I began to dig a little on it to get a wider picture. Now if we dive into the photo cycle itself I am wondering if the math works the same and wanted your opinion on it. A coral, specally a high light demanding coral has failsafe mechanisms with it to control the photo cycle and stave off oxygen saturation as a result of to much light. (one of the few things I liked about Dana's studies). What it shows is a saturation curve on the photo cycle in the wild. the photo cycle climbs on a steedy curve until it reaches a point of ...demishing return, from thier it begins to shut down until the cycle is completely stopped. I have back checked that data through a bunch of studies and it seems pretty conclusive. So now if we put that coral under artifical lighting I see the curve still existing but on a much more flat curve, but the point of deminishing return is still thier and so is the shut down process.
If we take that concept and apply it to the volume or total percentage of nutrition gathered by these types of corals would it put us back down to a few minor percentages required from external?? let me know yur thoughts


all else please feel free to jump in.



Mike

 

[Anthony Calfo]

wicked good question... I'm not sure I can offer an opinion on it sober. Oh... what the heck! I'll give it a shot.

Fantastic to see you mention compensation, saturation and photoinhibition points. I really wish more aquarists had a better understanding of the terms/processes. At the risk of a shameless plug, I tried to explain these aspects in laymans terms in my Book of Coral Propagation.

As for where these points fall in natural versus artifically illuminated corals... Hmmm... the diehard fan of natural sunlight in me wants to say that no artificial lamp could reach the same potential... and subsequently, could not reach the same high/optimal points of saturation. But frankly, I dont think its true. I do believe the same limitations in wild/natural illuminated corals (whatever extent/influences water quality/clarity have on these points)... would yield more or less the same results. That is to say, no... I dont think the compensation, saturation or photoinhibition points necessarily are lower in artifically lit corals.

The point is likely moot either way.

And aquarists need to realize, as you and I have both pointed out often, that even with corals that are 98% satisfied by the products of photosynthesis assuming we have "perfect" (artificial) lighting... that still leaves a net daily deficit of 2%. And that deficit unsatisfied will lead to attrition/starvation in that coral. It might take a year or more... but it will catch up!

And indeed, with us having less than perfect lighting (lamp color/quality/age... daily carbon/ozone use to insure optimal water clarity... wiping down dust/salt creep, etc off of lenses and lamps, etc... who really does these important things?)... even the most nearly autotrophic corals, those 98%ers and such, are ultimately not so nearly autotrophic - they are lower in practical applications.

And it comes round full cicrle again to feeding

Remember (all) you can make up for a deficiency in lighting with extra feeding (absorbtion and/or organismally where appropriate)... but you CANNNOT make up for a lack of nutrients/food with extra light (passing the saturation point... risking the point of photoinhibition). Thus... adding more light or leaving lights on longer is not the solution here. Its feeding baby!

kindly,

Anthony

 

[Illusion]

So Anthony,

Since you talk about over saturation Ect... What would you recommend running your lights for... 10hrs, 12hrs, 14hrs, 16hrs? I have had great success running a total photo period of 14hrs.. 11hrs mh and 14hrs Actinics.. My corals seem to be doing great... For food saturation since most corals are believed to feed at night I ocassion add some some of food at night as what I said "For the heck or it" Weather it be Marine Snow, Dts, Home brew phyto, Ect... I have always since I started in this hobby to feel how can something get everything from the light and there for IMO overfed the tank... I felt that It was to get used up in some form or another... I have had some algae issues in the past but have since corrected them and found a happy balance... All my acros seem very healthy and are displaying awesome colors...

James

 

[mojoreef]

man you type way faster then me..no fair, lol
Well from the studies I have seen on this as it relates to artifical lighting it does come into play on the overall equation. I believe a 400 watt MH bulb resulted in a 4 hour period before it hit saturation. I am not trying to move away from the feeding aspect, for me its a given, they all need food. What I am trying to do is to bring it down to terms of how much and and what. Knowing the budget given gives us a basis point at which to look deeper into the other..Not sure if I said that right but do you know what I mean??? lol
One of the biggest problems with hobbists and others is trying to bring these two worlds together when in reality it ends up screwing up both. Creating an enviroment that is completely nutrient starved and then trying to keep nutrient demanding corals in it. Or opposite creating a nutrient rich enviroment and putting coral in it that dont need or required. Maybe with some thought here we can find some parameters.


Mike

 

[Illusion]

With Nutrients I have personally decided with all this talk about phosban, Rowa ect why not Feed and use the Rowa/phosban to keep the levels down by the time it hits that area in the tank... When we feed its usually at the farthest point from most of our "high Tech" filtration devices... My thoughts have been If I feed like h3ll in the display tank it will only cycle thru the system for so long until either the Corals,Fish tank advantage of it or it gets removed by the advanced filtration techniques... I usually turn off the skimmer before feeding anything such as Marine Snow, or Dts however I feel that with the TFL phosban reactor cycles 80gph is recommended... In my system that would equate to all my water running thru in a bit more than 1hr... In my terms and I still feel like I am "stupid" in this hobby that means feed whatever I "think" my equipment can handle removing in a resonable amount of time... If it sits in our system for appro 3hrs and then is removed what is the harm... I mean most of us feed what every 3 days? what is the harm in just throwing food such as Phyto, Mysis, CE in there to the point of saturating the water column... If we look at the Ocean for example there is alot of mocro organisms in the water that are feeding corals at all times... Weather the corals use it is a different story however its avail at their disposal... I have a high coral load and a semi load Fish load so my usual feeding tends to target the smaller species of corals so I tend to make feed a majority of small particles and just throw a variety of "junk" into the water column... In about 1hr I turn the air back on the skimmer and let my system run as normal... IMO I feel comfortable with my system and what It can handle... Where most people who are "raising" corals should feel about their tank... I know if I feed this much it doesnt affect my levels nor do my corals look stressed... IMO I am a perfectionist and feel that I will probably keep upping the amount of food that I throw in my tank until I notice that just in Nitrates/po4 then let the system handle and process it then call that my Feeding goal... At or just below that Level... I like to for example throw the following on a every 3 days or so basis
1tsp Frozen or FD CE
1 cube mysis
semi small chuck cockle
1 cube Formula 1
small chunk Krill
and about once a week add 1-2 tbsp Marine snow after lights out

For my load I know that I am in others views overfeeding for my load but If It isnt hurting the system and my corals are growing/coloring up at an awesome rate then why not... I feel there is some organism in the tank that will use it in some way or another...

James

 

[Anthony Calfo]

James... please forgive me for using you to illustrate a point:

You are asking (me) for a recommendation for a photoperiod... but do not describe what species of corals will be kept (to address their specific needs... assuming they are even photosynthetic, how do I know without a list?)... and you do not mention lamp type(s), number(s) and intensities. This is a very common and sometimes tragic mistake that too may aquarists make. They want to know what hardware to buy before they select their livestock. Or worse... they buy it regardless of the livestock being kept. sigh...

So many of the corals we keep require such very different lighting schemes with respect for their natural habitats/preferences. Porites porites collected in 1 meter of water requires VERY different lighting than Blastomussa collected at 65 feet of depth where the illumination is mere single digit percentages of the radiance at the surface of the sea above it.

Later you mention you are mostly keeping Acroporids, but also mention feeding Marine Snow and at least two types of phyto. sigh (again)... I can assure you that very little of these foods are being used here. At best you are feeding your skimmer IMO. Well... perhaps an exaggeration... but not far from the mark. Dont get me wrong... there are some fine products out there. I think DTs is top shelf stuff! But do feed it to something that actually eats phytoplankton Much has been said on this topic in the archives or message boards and beyond. Do investigate further my friend. I apologize for not explaining more here, but currently I am struggling terribly for personal time myself. Every minute I am on the message boards is another minute my next book is delayed <G>

Mike... another thing to consider re: the light issue and threshold points like saturation in natural versus artificial lit corals is the source of light. We are comparing a static source (fixed artifical lamp) to a moving source (the sun in a path across the sky). How much effect does this have? I dont know. But I do believe it is something to consider (the moving source is more stimulating). And I do believe moving light sources (light tracks) have merit for experimentation beyond energy savings. Perhaps an influence on our topic here as well.

Anthony

 

[Illusion]

Anthony,

you are forgiven... If I can learn anything I enjuoy...

I mainly feed the Phyto and Marine Snow for my clams and... The CE and Mysis is more for sps-softies... I always kept it as a variety of different things... As for my system its mainly Acros and Montiporas with 3lg crocea clams, zoos other softies... My lights are 2x250w ushio 10ks with 2x110w Uri actinics... I know it doesnt really relate here as to what I run ect but a bit of explaination lol...

James

 

[NaH2O]

James, could you also indicate the size of your system - it will help me get a grasp on how much you are feeding (you indicated others view you overfeeding).

My train of thought is there will always be food available in a given system. How much food in order to keep corals thriving is dependent on what type of corals are kept, load, and filtration. In regards to SPS, I understand that perhaps the need for an external food source is greater than out on the reef, but these are closed systems, and should be thought of accordingly. Live rock is continuously spitting out detritus, there is bacteria, and a constant supply of waste of such things as fish and snails with continual break down through other organisms making particle size more appropriate to coral use. Wouldn't these things provide that <10% requirement for outside food needs? I just have a hard time figuring out the fine line of excess nutrients and starvation. I think for many hobbyists there will be an excess of nutrients, so when thinking "my corals need to be fed" we go and purchase some sort of "coral food" that is available, and end up overdoing it leading to constant algae problems. For sure, I understand what you are saying with regards to light only providing so much, and the rest of the requirements need to be met from another source. I am trying to get a handle on figuring out that outside source....if it is already available from day to day processes, or if more input is necessary. I suppose it is also a tank by tank basis. Man, generalizations in this hobby are hard to make.

I am struggling terribly for personal time myself.

You mean there is life for you outside this forum? LOL - it is difficult to reply to a topic like this with a 3 year old's help and her own opinion on the topic. I asker her if corals need to be fed....her answer "Nooo, Mom - their mouths are too small" (in an "are you crazy tone"). With some probing, she was thinking of big sized food, but the thoughts are there. *sigh* I'm a proud mommy lol - I'm sure if I ask her again in an hour she'll change her mind

 

[mojoreef]

Mike... another thing to consider re: the light issue and threshold points like saturation in natural versus artificial lit corals is the source of light. We are comparing a static source (fixed artifical lamp) to a moving source (the sun in a path across the sky). How much effect does this have? I dont know. But I do believe it is something to consider (the moving source is more stimulating). And I do believe moving light sources (light tracks) have merit for experimentation beyond energy savings. Perhaps an influence on our topic here as well

Agreed, I think the light being static would add to the over light consumtion, as most areas would recieve lighting for longer periods instead of the pass over by a rising and setting sun. Put the surface waves into play and even more of a spread is realised. Lets keep this going I think we can develope a concept here, I am diggin on my notes for ammounts and rates.

James your situation is exaclty why I want to dig in on this subject a bit more. Marine snow is basically detritus, phyto is just one thig a clam of that size will intake, your sps and monti's will not intake CE, Phyto, mysis or the other things you are feeding. So basicaally all the food you feed is for the softies and simular in your tank. Nutrient loading a tank to the point of saturation, can be ok, but not for alot of corals, for your softies, totally, for the LPS a little bit, for the sps really a bad idea long term.
This is sort of where we are going with this whole topic. We need to find the ammount the energy budget realized through photosynthisis, from thier we can dig into what ammounts need to be added.

Nikki thats where I am trying to go with this. thier are formulas and means of doing this, so lets dig somemore


Mike

 

[Curtswearing]

To make sure that we are all on the same page, I wanted to give you the definitions that Dana Riddle used in his study. This information is from a link in the library called Lighting FAQ and Bulb Color Comparisons by Dana Riddle

Photosynthesis is a biochemical reaction in which carbon dioxide, water and light energy ultimately produce oxygen and carbohydrates; it is a link between the inorganic and organic worlds. The rate of photosynthesis is generally proportional to the amount of available light. Light quantity (intensity) and quality (spectral composition) are important for plant growth.

The “Z” Scheme for photosynthesis. see thumbnail...cs Light energy is harvested by Photosystem I (PS I) and Photosystem II (PS II). Oxygen evolution occurs in PS II; an interruption of reactions in PS II stops the electron flow to PS I, thus effectively stopping photosynthesis.

The photosynthetic electron transport system in all oxygenic organisms is composed of Photosystems I and II. Both systems include special forms of Chlorophyll A – Photosystem I includes a form of the Chlorophyll A pigment with a specific absorbance of 700 nm (red light) that is called P-700. Photosystem II contains the reaction center responsible for oxygen evolution; it contains a special Chlorophyll A that absorbs light at 680 nm (red light) that is called P-680. Photosystem I is dependent upon the proper functioning of Photosystem II – if the photochemical reactions in Photosystem II are inhibited, Photosystem I is inhibited as well.

Zooxanthellae contain chlorophylls A (both P-680 and P-700 in addition to “regular” Chlorophyll A that collects light in the violet, blue and red portions of the visible light spectrum). Pigments that harvest light energy outside of 680 nm and 700 nm and make it available for photosynthesis are called Accessory or Antennae Pigments. Antennae pigments include Chlorophyll C2, peridinin and beta-carotene.

Photosynthetically Active Radiation (PAR): A measure of visible light intensity (400-700 nm) obtained by using a quantum meter. PAR is simply a count of photons falling upon a surface in a given time and is reported as “micro Mols per square meter per second” (µMols·m2·sec). Quantum meters report all wavelengths between 400 and 700 nanometers. However, they report only light intensity and do not account for spectral quality. Generally, maximum solar PAR values are 2,000 – 2,100 µMols·m2·sec. PAR is something of an outlaw in the scientific community; it is not recognized as a standard unit, however most major works in the field (notably Kirk (1983), among others) state compensation and saturation points (see below) in PAR units. (Since PAR is a relative new-comer to science, it has not been recognized by CIE (Commission Internationale de L’Eclairage) or the International System of Units (SI) – both had already adopted standards for measuring light intensity. Lack of recognition by either of these committees should not undermine the importance of PAR measurements. Incidentally, divide µMols·m2·sec (of sunlight) by 4.6 to convert to watts per square meter per second (which is a SI-recognized unit.) A quantum meter is better suited for reporting light intensity than lux meters. Lux meters are photometric in their response, that is, they “see” light as the human eye does and have a maximum sensitivity to green wavelengths. The human eye is not especially sensitive to those wavelengths known to promote photosynthesis (violet, blue and red). Generally, noontime lux measurements made on cloudless days in the tropics range from 100,000 – 120,000 lux.

Maximum PAR is the highest measurement made under standardized conditions (for our cases, the lamps are 3.5" above the PAR sensor. This replicates the distance from the lamp to aquarium water surface in many cases.

Blue PAR is determined by using the PAR sensor and subtracting glass cut-off filters. A yellow filter removes blue wavelengths, red removes green, and blue removes red. The amount of radiation subtracted is added together and the "blue" PAR is divided by the sum of all 3 to arrive at an approximation of broadband PAR in each case. (These are exact, but since all lamps are tested under the same conditions, it allows us to compare lamps.)

Compensation Point is usually defined as the minimum amount of light required for oxygen production to meet the zooxanthellae/coral host respiratory requirements. Corals have the ability to absorb oxygen from the surrounding water (as they do in darkness); however, insufficient light energy may also result in low production of photosynthetic lipids. During periods of prolonged darkness (or inadequate light) zooxanthellae will then use their energy reserves until they are depleted and a sort of starvation occurs, usually resulting in irreversible damage or death. Compensation points vary from specimen to specimen and often depend upon their light history. Compensation points in low light adapted corals may be just a few µMols·m2·sec or much higher in high light adapted corals (350 µMols·m2·sec or ~17,500 lux; see Kirk, 1983). It should be understood that light intensity should exceed the zooxanthella’s compensation point.

Saturation Point Photosynthetic rates are proportional to light intensity only to a certain point. The Saturation Point has been met when photosynthesis is at a maximum, and increasing light will no longer increase the rate of photosynthesis. Saturation occurs when the photosynthesis electron transport systems are operating at full capacity. Exceeding the saturation point is pointless, and from a practical standpoint, results in needlessly high electric bills. If light energy greatly exceeds the saturation point, Photoinhibition may occur. Photoinhibition is generally defined as any occurrence interrupting the normal electron flow in photosynthesis. There are two types of photoinhibition – dynamic and chronic. The first is chronic photoinhibition that involves irreversible damage to Photosystem II and were synthesis of new “photosynthetic proteins” must occur before normal photochemistry may resume (Brown et al, 1999). Dynamic photoinhibition involves reversible photochemical reactions that divert excess light energy away from Photosystem II through thermal dissipation. This “quenching” of photosynthesis involves reversible changes in xanthophylls diadinoxanthin and diatoxanthin. Dynamic photoinhibition protects the zooxanthellae (through absorption of violet through yellow-green wavelengths of 400-550 nm) from high levels of photosynthetically produced oxygen radicals, including hydrogen peroxide. Not all strains of zooxanthellae have the ability to produce xanthophylls and therefore may have little resistance to the effects of high light intensity.

 

[mojoreef]

Wow Curt thanks for the definitions

Anthony when crunching the numbers and keepin in mind the difference in intencity, saturation points, deminishing returns, rise and fall of the sun and so on and on, I am looking at about a 10% reduction in useable light for coral, or the corals are recieving about 10% less food from photosynthisis. That sound like a resonable number??


MIke

 

[jks1]

an interesting definition in Craig's post:

Compensation points vary from specimen to specimen and often depend upon their light history. Compensation points in low light adapted corals may be just a few µMols·m2·sec or much higher in high light adapted corals (350 µMols·m2·sec or ~17,500 lux; see Kirk, 1983). It should be understood that light intensity should exceed the zooxanthella’s compensation point.

Would this indicate if proper acclimation is used that the coral can optimize its compensation point to match that light it is recieving in our tanks? I'm sure there is a minimum value which I think is what Mike is trying to determine, and also a maximum value.

For instance in my tank 84"x24"x24" (210g) I run 3x400 MH XM 10K, and 2x96 PC actinics. Although Ive seen no "burning" symptoms in any of my SPS, some corals do not do well higher in the tank. In order to get polyp expansion in some green Ricordea florida I have, I had to place them under ledges.

Very interesting thread- will be watching

 

[Anthony Calfo]

it does sound reasonable/believable indeed. Of course, I'm stoned out of my mind presently on allergy medicine. Darn ragweed! Or really, is it so bad after all? Hmmm... I think I'll go back to staring at my hand while you chaps keep digging for more great reading

Anthony

 

[mojoreef]

John I am trying to determine a value or percentage of what corals get through Photosynthisis. I know the values they get in the wild, but our lighting is not the same, so thier is going to be less, once we come to an agreement I can adjust the values and thn we will know what percentage of outside food source corals need.


Mike

 

[Illusion]

James, could you also indicate the size of your system - it will help me get a grasp on how much you are feeding (you indicated others view you overfeeding).

Nikki, My total water volume is right around 100g... My main display is a 55g glass tank with a 20g prop tank and a 60ish gal sump..

Now i have to go back and read the rest LOL...

James

 

[LvFishguy]

Okay, sorry to jump in here kinda late but, is the same true also for sea Anenomes as a whole? I know that they are a very light driven animal but, can you suppement lack of light with food?

 

[Curtswearing]

LvFishguy,

WELCOME TO REEF FRONTIERS!!!

Anemones, like other reef-dwelling creatures, have evolved over a long time and have managed to adapt to their environment. Our tanks do not properly reconstruct their environment with regards to lighting so a little extra food will do an anemone well. However, we can't put an anemone in a low light situation and try to offset the low light with extra feedings of food.

 

[LvFishguy]

A low lighting situation is I given...I guess my question is that, Anemones are reliant on phytosynthsis, but how reliant are they really.
Most reefer that you talk to say that they must be kept only under MH's but, I have met more than my share of people that claim that they have kept them under PC's for more than a year and I have even talked to one person that has been coming to my store for a number of years that has had a Seabae that has split multipule times.

 

[Llarian]

Hm, this is an interesting thread...

Anthony has mentioned a couple times his suggestion that corals with similar lighting needs be kept in the same tank, rather than mixing and matching, even within the same family. (Or is that genus? I can never get my taxonomy straight)

I've been thinking about that for my own not quite built tank, and it seems finding good information as to what corals need what is really difficult. About the closest one can usually find is SPS are high light, high flow, which obviously isn't true for all of them, but that seems the general wisdom out there.

So, I guess my question/tangent is, where does one look for that information? If I want to set up a reef biotope, rather than a garden, where can I find the information I need to decide that a particular set of species have similar environmental conditions?

(I personally think Anthony needs to finish the next book in his Natural Marine series, but that's just me. =)

-Dylan

 

[Anthony Calfo]

Its a good question, Dylan... and the information (biotopes) is really a lot easier than you might expect. An enormous amount of it is sitting... right here(!) on RF. No kidding, literally! Our fearless founders of the site spent more than a few pennies getting permisison to use Veron's data and images on scleractinia from his most recent 3 volume work (a veritable treatise).

And so... if you say you love elegant corals and you want to set up a biotope around them, look to a thorough reference, field guide, etc for data on their distribution, occurance on the reef, depth, etc. With that, you can go most anywhere (NOAH for starters) and get additional information on salinity, water temps, etc.

Continuing with this example... go to the top of the page, tage the link for ID research gallery (ahem! note: "research" <G>)... and help yourself

From there we go to "coral IDs"... then "Large polyped stonies"... then "Blastomussa/Barabattoia/Catalaphyllia "... then "catalaphyllia"

Now in this case, I did not pick/use a stellar example. Beyond the decription of the animal, we only have:

"Habitat: Occurs in protected, preferably turbid water. Abundance: Seldom common but conspicuous. Rare in the western Indian Ocean."

But its a start... we have the animal's name, locale and general preferences. We can take these terms/phrases and do keyword searches for more info abroad. You can also go to excellent booksellers of scientific, field and academic works like seachallengers.com to find regional field guides that will include your target species and so much more.

It really is a journey But so much fun. And the info is there... simply waiting to be discovered. Of course, detailed hobby literature like Eric Borneman's "Aquarium Corals" provides a tremendous amount of information to work from or make logical conclusions. And then, theres practical experience... many folks on these message boards are avid divers and can attest to sightings of species and params from firsthand experience in common travels to Indo, Phillipines, Tonga, Fiji, Red Sea, etc.

be resourceful, my friends.

As they say, "... teach a man to fish, he eats for a lifetime."

Anthony