"pastel" colors vs. deep dark coloring

[stony_corals]

According to Shimek, Borneman, Sprung,etc, For a dsb/jaubert plenum, they recommend to not disturb the sand beds. I've have always been a bit lazy on tank maintenance... the only thing I have siphoned was stuff in the sump.

I've had systems that had the pockets of detritus build up, but didn't exhibit any PO4 in the water column. I think what many of the author above have written about is that detritus is part of important food webs, so I don't sweat detritus too much, unless its in the front and makes the tank a bit unsightly.

I'm not sure if PO4 can contribute to a darkening of acros, I'd speculate (it is only a speculation) that NO3s and other nitrogenous compounds contribute more to the browning out. Why? Nitrate is essentially a plant fertilizer, and by having larger amounts than what the coral is used to causes the zoox to multiply to a much larger population. Therefore the coral turns brown. One thing I'm curious to know and understand better but won't necessarily come from hobbyists is the answer to the question of whether our tanks really are nutrient (N,P,C) starved. All our test kits test for inorganic molecules of those elements. Meaning, if ammonia, nitrite, and nitrate test at 0PPM, these are all inorganic molecules.... What about dissolved organic nitrogen?dissolved organic phospates? In the third Sprung/Delbeek book, Delbeek show that a system at the Waikiki aquarium had higher than NSW levels of DON and DOP over a three year period, whereas the inorganic N and P that everyone tests for were near NSW.

There is a lot we do not understand about what happens in our reefs, because we can not test accurately for many of these nutrients/ions etc. It also makes it difficult because it's challenging for the hobbyist to isolate one variable in our systems and that our brains were designed to make associations as a survival mechanism, where they may not exist.

Also, if you're really interested in knowing what your PO4s are, I'd go with the Hanna or Deltec/Merck test kit. Pretty much all other PO4 test kits aren't that accurate.

 

[Kolognekoral]

A great thread, to say the least!

I've experienced changes in my coral colours and have found two major influences; NO3 and Trace Elements. PO4 doesn't seem to have a direct effect.

I say direct as, according to new studies, the balance between available NO3 and PO4 is key to coral metabolism. I wish I could refer you to the article(s), by Kokot, but they are in German. If there is insufficient PO4, the corals tend to dissolve from the base in an attempt to save themselves. I think many of us have seen this. The other extreme is too much NO3, which pushes the metabolism of the Zooxanth. and the coral darkens to a brown.

Now brown is not dark blue! I am convinced that the blue corals are less easily influenced, although the pastel blues will show a change when the NO3 is too high in that they darken and oft become more attractive , in some eyes, anyway. This does make sence in tha the blue corals seem to possess more pigment and are capable of remaining blue, despite high Zoox. levels.

Rose and pink corals, as well as many greens, tend to go brown or reddish. Often this is, also, attractive, but brown ain't my thing!

Now, I have recently been filtering with a Zeolith and noted a nutrient reduction, assumedly via ammonium reduction. The corals are getting paler after one week. Nothing shocking, just paler.

I have a DSB refugium attached to the reef and this has shown a reduction as well, with the algaes not growing quickly. To attempt to adjust this, my skimmer is now turned off. I suspect it competes too much with the DSB.

Facit: I like my DSB, so it will remain on the system. Not to mention that the other animals benefi from the critters that flow into the reef.
I want to continue with the zeolith, as it keeps my water clear and does maintain a stable environment, which is my main goal.

I can use the skimmer if things get out of control, but I will feed my corals and fish (I have a lot!) in the sense of maintaining a stabile environment.

I do believe lots of animals in the aquariun do make for a stabile environment, when they remain in balace to the filter system. Plus, their metabolic wastes (poo, to the rest of you ) do help the various lower animals.

OK, whatdya think?

 

[stony_corals]

Jamie, wie gehts? Ich habe im Koln geht, es war 15 jahrs. Mein deutch ist niche so gut....

Is the Kokot article the one about vodka? I'm not remembering that one.... The Zeolithe ( are you using the ZEOvit zeolithe?) do absorb ammonia, but also become the site for nitrifying bacteria cultures, though I think that given a slow enough flow through the zeolithe reactor, denitrifying bacteria also are developed.

You mean you aren't concerned about your DSB becoming a nutrient sink and causing your tank to crash?!?(I'm joking...). I've not heard about the insufficient PO4 causing basal tissue recession before, though I've heard that a lack of flow and too high of alkalinity causing that. (All anecdotal...)

I'd recommend you turn on your skimmer during the night though... Your tank inhabitants would all respire CO2 during the dark period, so that may cause issues, unless your refugia is lit the entire time.

Again, I'm having a difficult time with our tanks being totally nutrient poor as I referenced the Delbeek aquarium at the Waikiki Aquarium showed higher levels of organic P and N relative to NSW. Either way, I don't know, it could be that we're trying to blame something (pale colors) on something ( low 'nutrients') where the association does not exist.

I've more questions than answers....

 

[RichConley]

"I'm having a difficult time with our tanks being totally nutrient poor as I referenced the Delbeek aquarium at the Waikiki Aquarium showed higher levels of organic P and N relative to NSW"

I haven't seen the Waikiki aquarium, but I have seen some of the other famous coral displays around the country, and it is my oppinion, that very many of us have cleaner environments than these displays. Whether thats good or bad, I dont know, but all of these systems seemed to have what us hobbiests would deem an extreme amount of particulate in the water.

 

[stony_corals]

The Waikiki is quite impressive... I hear what you are saying, but IMHO since there aren't any tests for organic N and P compounds, we can't truly say whether or not our systems are nutrient starved. We simply can not measure or prove this, nor disprove this.

 

[RichConley]

no, I know, my point was that the fact that the Waikiki aquarium was higher than natural doesnt mean that the average hobbiest that complains about lightening is.

 

[Kolognekoral]

Stony,

the Jörg Kokott article is part of a 7-part series that was published in Koralle during 2004-2005. As Koralle is now available in English as Coral, the serie may be reprinted. They probably have reserves the rights to the series. Translated, the name would be 'Nutrients in the Reef Aquarium'. He discusses all the various components of the nutrient cycle and builds a big, if somewhat complex, picture of the reef environment.

As I understand, J. Kokott is currently studying on the GBR in Australia and may have published some papers for his degree. Where one finds them is a good question. Often these academic sites require a paid membership before you can access.

As for basal tissue recession, I know that water flow is a factor, from personal experience, but this type of tissue recession is typically in responce to less than optimal gass exchange at the base, so the coral simply reabsorbs the extra tissue. The reaction with the PO4 limitaion is very rapid and the entire colony can dissolve in 24-48 hours! Possibly we have a bacteria component here as well, but from what I've read, no specific consistent pathogen has been isolated. In most cases, pathogens are opportunists and simply take advantage of the situation, rarely are they the direct causal.

I think there is a real grain of truth in the low nutrient philosophy, but the aesthetic side is not to everyones liking. I have corals that look their best when the nitrates are around 10ppm, with their colours being much more saturated. Now, those of us prefering the more pastel tones should avoid too much NO3 as this will increase the zooxant. production and darken the coral. I have one coral that went from flouresent green to cocoa brown and I would like to see it more to the green! . I currently am running a low nutrient program and see the first signs of lightening, but it is slow.

As to adding nutrient supplements, such as amino acids and organics, this is an interesting approach and, when one learns what dosage for them is correct, it is an fascinating tool.

I know of aquarists in Germany that actually manage to model the colours of their corals with aimed dosing of specific trace elements, such as iodine, eisen, strontium, etc. I am not that far and, frankly, I am not sure I want to model the colours. I am a fan of letting nature follow her own devises, she's been at it much longer and I always manage to gleen new knowledge from her tried and true systems.

I hear you on the DSB competing for O2, but it is a few hours shifted from the reef, so we experience only 6 hours of total darkness in the system. I am keeping an eye, though. Thanks for the reminder.

Again, always more questions than answers, but that is the very reason that we all enjoy these forums so :

 

[stony_corals]

Jamie,

It sounds like an interesting article, I'll try to see if I can get reprints.... What I've used to find scientific articles is google scholar (http://scholar.google.com). I'll check and see if his name results in anything.

With going to really low nutrients, it's good to go slow to allow the coral to adapt. I think this is where a lot of aquarists run into issues with the probiotic approaches - they can lower them very quickly.

Are you using ozone or uv? What supplementation are you adding?

 

[stony_corals]

<a href=showthread.php?s=&postid=9148006#post9148006 target=_blank>Originally posted</a> by ReeferAl
No they aren't. See my previous post. They wouldn't act like PO4 because they aren't PO4. Phosphate (PO4) can get into the calcium carbonate crystal lattice and stop the process of calcium carbonate deposition. It "poisons" the crystal formation. Organic phosphates are large molecules that aren't able to do that, even if they "wanted to".
Allen

Allen,

I appreciate your thoughts. I found this article that shows that organic phophates can limit calcification.

The effects of HEBP, an inhibitor of mineral deposition, upon photosynthesis and calcification in the scleractinian coral, Stylophora pistillata. Yamashiro, Hideyuki. J. Exp. Mar. Biol. Ecol. (1995), Volume Date 1995, 191(1), 57-63.

Also referenced in http://www.advancedaquarist.com/issues/apr2002/chem.htm, specifically "Organic phosphate and phosphonate inhibitors of calcification have also been studied and probably work by a similar mechanism. HEBP, a bisphosphonate that is shown below, causes a 36% inhibition of calcification in Stylophora pistillata at 10 mm, and stops it completely (99%) at 500 mm."

 

[Kolognekoral]

Stony,
I am using UV, as my Acanthus leucosternon is a bit sensitive. I was never a fan from UV until I had this doctor, not I've learned to work with it.

I do not have the entire circulation running through it. It runs with an Eheim canister, about 600lH (150galH.) and this is sufficient to maintain my doctor.

As far as I can tell, this has little or no effect on colouration of the corals (and really doesn't belong on this thread, therefore!).

 

[stony_corals]

Jamie,
I understand. Well in many articles that mention how Europeans maintain reef aquaria, it is frequently mentioned that ozone and uv are often employed. When I was in Europe years ago, I found as many did as didn't. But the reason cited in these articles is that ozone and uv help create a more 'sterile' environment and therefore colors tend to be better in Europe.... Just my curiousity...

 

[Kolognekoral]

Stony,

interesting hypothesis, but I can't see why a sterile environment would help. Ultimately, we are seeking a low nutrient environment, which shouldn't be confused with sterility. I understand a sterile environment as one with less life, particularly microlife. I have been advised to discontinue my use of UV as it breaks down amino acids, which are a typical SPS suppliment these days and kills bacteria which are an important part of the new feeding philosophy. Now in this sense, I believe UV may have a deliterious effect on colour production, as many bacteria are associated with the production of raw materials that may find their way into pigment production (saved ) . I know very little about pigment production, but the series of articles running in Advance Aquarist by Dana Riddle may hold some clues. I'll have to check 'em out, again. Here are the adresses for two out of (I think) 4 parts.

http://www.advancedaquarist.com/2006/11/aafeature2

http://www.advancedaquarist.com/2006/9/aafeature

I forgot to mention, I have only been adding an Amino Acid supplement from Timo, Iodine from Elos and feeding relatively heavily.

 

[stony_corals]

Jamie,

I can't say it's my hypothesis... just some reading on the Internet That's one of the key reasons I've stayed away from them (UV and Ozone) - killing bacterias, breaking down aminos (which I add as well). Good articles. Are you using a probiotic approach?

 

[Kolognekoral]

Yes and no! I am at a cross-roads and do use some of the Zeolith filtering products, but, as I do have the UV and a refugium, the probiotic approach is too strick a philosophy for me. The refugium has a DSB, is full of interesting small critters and regular blooms of plankton are washed into the main reef every evening. Last night was particularly immpressive as it was full moon (according to my lighting). I do think this does help the corals maintain better colour in any case. Apparently, Acroporas cover some 70% of their energy needs with plankton, not through the zooxanthellae. The zoox. provide the sugars, but the protiens are taken up via plankton ingestion and probably osmosis as amino acids.

I read an interesting article, again in German, about an aquarium maintained without the actual Zeolith filter medium, but with the addition of the supplemental products. The colours were electric and almost too much for my taste, but I think one can control the intensity via proper dosing. This is where I am heading, with the refugium/DSB as the main filtre, carbon, occaisional skimming and small amounts of supplements. This system is running about 4 months and I have almost no nitrates and the PO4 is my only real concern. For this I am culturing macroalgae in the refugium. This still need more time to fully develope.

During this time, my corals went from light to dark and are now becoming lighter once again, which seems to signal a stabile environment.

 

[Big E]

Apparently, Acroporas cover some 70% of their energy needs with plankton, not through the zooxanthellae. The zoox. provide the sugars, but the protiens are taken up via plankton ingestion and probably osmosis as amino acids

I believe you have that backwards. The zoo can provide 75-95% of the coral's demands. I read this many times & thought it was common knowledge. This is according to Sorokin....

Some info provided here......
http://www.reefs.org/library/talklog/e_borneman_051098.html

"Indeed, corals do actively feed on bacteria in the mucus, in the water, and attached to particulate matter. They typically utilize them for 5% of their diet, by weight. This is on an efficiency level on par with many of the specialized filter feeders and sponges. Sorokin found that, in general, bacterioplankton ingestion alone can provide from 8-25% of the coral’s respiratory demands. This amount is the equivlent of 1-10% of the animals total biomass per day...from bacterioplankton!! Its assimilation index by nutritional content is the equivalent to the nutrition acquired by the capture of small crustaceans (which are by weight, much greater and a greater energy expenditure to capture). Phosphorus, a normally limiting resource in coral reefs, is found in the cell walls of bacteria. Coral consumption of bacterioplankton provides them with a more easily assimilated source of phosphorous than from the uptake of inorganic phosphate contained in the water. "

 

[Horace]

I would like to add one more little side topic about color and Zoox. I think there are two separate things happening here that are sometimes automatically assumed to be the same thing. That is that the richness of color is directly related to the zoox population. Im not ENTIRELY sure there is a perfect connection. Now I do agree that if you have too many zoox your coral will turn brown (color covered by brown zoox), however, there are plenty of corals that have neither color OR Zoox. I have a few corals in my tank that have been stressed that have almost no color on them, and you can visibly see there is very little zoox as well (essentially bleached). I think what we really need to figure out is how to get a coral to produce COLOR, yet not produce a bunch of Zoox.

I would also like to say my Zeo tank exibits quite a few corals with what I would call pastels as well. Peticularly my green corals. My green slimer, green caps, green pocillapora, green digi, ALL show very light colors. Some of my others are pastel as well but not as noticeable as my greens. Basically they are more of a yellow/green rather than the deep green that I have seen these corals in the tank they were fragged from (GQJeff's Zeovit tank).

I have been fighting this for nearly a year now and I have only been able to slightly change the greens for the better. About the only thing I have not tried is adding more fish. I have increased my feedings, and that seemed to help some, but not dramatically. The past two weeks I have tried doubling the amount of Aminos I dose to the tank, but I have yet to notice any difference. I am going to continune with this for atleast another month and see if there are any results. I would really rather figure out how to better feed my tank than to add fish. Though adding a higher bioload on the tank MAY work, im not sure that is really the answer. I think that will lead to more phosphate, and I would rather just raise the Nitrogen alone.

One other note, I have NEVER been able to grow chaeto in my tank. It looks ok (I dose iron), but it doesnt grow at all. I think this is an indication that my tank is very defficent in either N or P or both as well.

 

[Kolognekoral]

Big E,

in the article I read (wish I had bookmarked it, now) it was clearly noted that most corals require extremely large procentages of zooplankton in their diets to grow and prosper. The zooxanthellae only provide them sugars. Now to maintain themselves corals would be able to continue on just sugars, but in order to reproduce, grow, produce pigemnts, they must have other nutririon. This really only makes sense, we all know how effective sugars are for human energy spurts, but living from them is another thing.

Acros (those tested were often unidentified) were noted in the research as typically covering 70% of the nourishment through zooplankton. As I understand it, this was under 'natural' conditions, which I take to mean a NSW type situation, as found on a reef.

Now, I had previously read that corals get most of their nutrition from zooxanthellae, this was some 20 years ago. It appears the experiments only indicated that the coral COULD survive under such a diet. I have never seen a reference to growth rates or reproduction in cinjunction with these early experiments.

In another article I read an interesting tidbit on extended polyps; those corals that extend their polyps mainly during daylight are considerably more dependant on their zooxanthellae and the polyps tend to have a colourless body. Those that extend their polyps at night are most heavily dependant on zooplankton, they, also, tend to have highly coloured polyps. OK, this clearly makes some sense, a coral does not waste energy extending its polyps at the least advantageous time.

Now, maybe this has some correlation to coral colours! If the zooplankton loving corals also have more colour, then it may well be that the protiens are a key factor in manufacturing pigment. Amino acids are the building blocks of protiens. Hmmm

On the subject of pigment, does anyone know which types of pigments have been isolated in corals? Are anthocyanins present or are they generally lipid pigments. I ask as anthocyanins are interesting in producing blues in an alkaline environment. They vary the tone via hanging sugars onto the main molecule.

Horace, I agree 100% with you here, symbionts and pigments are two different factors working side by side. By increasing the zooxanthellae numbers, we are creating a darker backgound for the (chromo)pigments. Similar mechanisms are found all through nature, such as parrot feathers that refract light to create whate we see as green. There is no green pigment involved, it is yellow plus a refractive- blue structure in the feathers that give the impression of green. Cool!

As to adding fish to increase the available nitrogen...why not? I plan on adding a small school of Anthias to my tank to increase available nitrogen. In my eyes, it's the more enjoyable solution than dosing nitrates from a brown bottle :rollface: I really think it boils down to deciding what one wants to see/have and aiming for this goal. There are generally a few roads heading in the right direction. I have started feeding a powdered diet in the evenings, when the polyps are extended and my corals are becoming a bit lighter in tone. Maybe this helps them rearrange their metabolism to require fewer zooxanthellae? May just be anecdotal BS!

Just some thoughts,

 

[Obi-dad]

<a href=showthread.php?s=&postid=9247284#post9247284 target=_blank>Originally posted</a> by Horace

One other note, I have NEVER been able to grow chaeto in my tank. It looks ok (I dose iron), but it doesnt grow at all. I think this is an indication that my tank is very defficent in either N or P or both as well.

My chaeto growth stopped after installing a much larger skimmer and using Phosban. My tank has always measured 0 for nitrates. I have recently started dosing 2ppm KNO3 daily, and my chaeto has doubled in size in a week (the tank measures 0ppm nitrate again by the next day). I think that my tank has a lower ratio of N to P than normal. I haven't noticed any difference in coral colors yet, but I have only been doing this for a week and changes of coloration in corals is normally not very rapid (other than going to white because of bleaching). I am hoping to see increased colors in my corals, right now they are pastel.

 

[stony_corals]

Big E, the thought that a corals zoox could provide all the energy a coral needs is pretty old. Photosynthesis of the zoox only supply the host coral with sugars via translocation. In order to grow, the coral needs a source of N and aminos. This is what fish poo, probiotic, and feeding fish more provides.

 

[Big E]

If it's old.......show me some scientific data that has changed this?

How bout some links.........where are these facts located at?