the secret to colorful,healthy corals....obvious to some,elusive to many

[DiscusHeckel]

This is a very interesting thread. I thank all of you who contributed.

Here is a quick summary of my set up:

I have a 250lt (net volume) shallow reef tank in which I keep four large clams (approx. 5" each) along with SPS and LPS corals (no soft corals except a few mushrooms). I do not have sand bed in my display tank or sump. I rely mainly on cheato and water changes for nutrient export. I fluidise Rowa Phos and Seachem matrix carbon in two different reactors. I run a Bubble magus Nac 6a protein skimmer 24/7. I replace just over 10% water every week. Here is the list of fish I keep:

1 X yellow tang
1 X Genicanthus melanospilos
4 X Chalk bass (Serranus tartugarum)
1 X checkerboard wrasse (Halichoeres hortulanus)
1 X blue reef chromis (Chromis cyanea)
1 X Royal gramma (Gramma loreto)

I feed my fish 3 or 4 times a day heavily with flake food and frozen food.

NO3 levels are 0 (Salifert) and Phosphate levels are also 0 (Rowa Merck high sensitivity test kit).

Yesterday's test results were as follows: KH 9.3 dKH (Salifert), Ca 425 ppm (Salifert), Mg 1355 ppm (Salifert), Potassium (Salifert) 410 ppm. KH, Mg, Ca, K test kits have been calibrated with Fauna Marine Multi Referenz solution.

I use a 6 X 39W ATI Sunpower unit (4 X ATI Blue plus, 1 X ATI coral plus, 1 X KZ fiji purple and 1 X 6500K). PAR readings vary from 265 + mmol to 450+ mmol depending on the position of corals and clams on live rock. All my SPS corals and clams get over 350 + mmol PAR (These Apogee readings have not been adjusted for blue spectrum, hence the "+").

Now the coral colouration:

My SPS corals always exhibit pastel colours. Do not get me wrong. The colours look OK, but never vibrant and deep. When I raise the ATI unit, they start to look brown, whereas if I lower it they start to look pale. Soon after I place an acropora coral in my tank, it loses its original colour within a few days. I tried dosing trace elements, amino acids, iodine and potassium with no appreciable difference in the past. I always ended up having cyano. I no longer dose anything other than Kent Marine chaletaed iron once a week and Salifert Iodine once a month (only after testing though!).

Having read this thread, I have decided to lower the alkalinity levels to 8.4 dKH over the next 10 days initially. I will then reduce them to 8 dKH, and will report back any changes in coral colouration.

In the meantime, I would like to ask you if in your opinion very low nitrate levels may contribute to dull colouration too. I have just checked my log file dating back to 2008. The information I kept suggests that whereas alkalinity levels varied (between 8 dKH to 10.5 dKH), I always obtained trace nitrate readings with my Salifert test kit (between 0.1 ppm and 0.2 ppm). Despite feeding my fish very heavily, nutrient levels never increase in my tank. I believe that my clams are the biggest consumers of free nitrogen and phosphorous in the water column. Finally, although I have a lot bubble algae, I have no micro/macro algae growing on live rock. I get green/brown film algae on tank glass once every two days. Referring to the biomarkers mentioned in this thread, do you think I should not assume that I have a low nutrient reef tank due to large number of bubble algae?

Any advice would be appreciated...

:beer:

 

[sirreal63]

This is a very interesting thread. I thank all of you who contributed.


In the meantime, I would like to ask you if in your opinion very low nitrate levels may contribute to dull colouration too. Referring to the biomarkers mentioned in this thread, do you think I should not assume that I have a low nutrient reef tank due to large number of bubble algae?

Any advice would be appreciated...

:beer:

Just my opinion and experience but I believe nitrates and phosphates are important for coloration. Nitrates IME seem to have a larger impact than phosphates. If I keep the NO3 at 3-5 (sometimes as high as 7) I get the deep colors I want. I try and keep the PO4 at around .04, and I too have a lot of Valonia which I remove often but I can't get all of it so I live with it. I don't complain because I am getting the deep colors I want. I feed pretty heavy for the small fish load I have, and I believe that helps. I also feed a heavily puree'd seafood mix for the corals and other life in the tank. I truly believe too many people starve their corals and the tank in general.

It may be true that on the reef the PO4 and NO3 levels are extremely low, but the amount of food is massive and we just cannot replicate that in our tanks so having some extra nutrients that are not available on the reef helps with coral health, as long as it is not excessive. Unfortunately what is excessive in one tank may not be in another.

 

[DiscusHeckel]

Just my opinion and experience but I believe nitrates and phosphates are important for coloration. Nitrates IME seem to have a larger impact than phosphates. If I keep the NO3 at 3-5 (sometimes as high as 7) I get the deep colors I want.

Thanks.

I will first experiment with NSW level alkalinity levels. I am really curious to find out if it will help. If I do not get anywhere with it, then I will dose NaNO3 in a controlled way and raise NO3 levels to at least 0.2 ppm.

I do not want to change too many parameters in one go.

Has anyone else observed any correlation between NO3 levels and coral colouration?

:thumbsup:

 

[Nano sapiens]

Thanks.

I will first experiment with NSW level alkalinity levels. I am really curious to find out if it will help. If I do not get anywhere with it, then I will dose NaNO3 in a controlled way and raise NO3 levels to at least 0.2 ppm.

I do not want to change too many parameters in one go.

Has anyone else observed any correlation between NO3 levels and coral colouration?

:thumbsup:

I haven't had a NO3 or PO4 reading (Salifert) in years, but of course both are in the system and being used by various organisms.

Each tank has it's own quirks, but in my tank increased feeding frequency of a variety of foods along with lower Cal and Alk levels (~420 and 7.8, respectively) has been crucial to increasing the richness of coral coloration and growth.

 

[SantaMonica]

Of note might be the visible growth on your glass in 2 days. This is pretty quick, and says that you might have higher ammonium/urea levels in the water (from the fish) before the water ever gets to a filtering mechanism. High feeding can do this, especially if in large single events; better is several smaller feeding events (or continuous) so the ammonium can be dispursed/filtered.

However, more ammonium hitting the corals would seem to me to cause darker color, not lighter.

 

[Dummy]

any updates from people who made these changes to their tank?

 

[dkeller_nc]

If we wouldn't keep a hamster under such foul conditions, why would we keep animals, from one of the cleanest environments on the planet, under such foul conditions and expect them to do well?

There's only one difficulty with this analogy (though I certainly understand the logic). Coral reefs are not so nutrient poor as has been previously assumed. Yes, it is very true that the seawater around them is extremely low in dissolved, mineralized nutrients such as PO4 and NO3.

But overall, they are bathed in a nutrient bath of zooplankton and phytoplankton, which is not something that we can currently reproduce in our tanks. The extent of this wasn't recognized until very recently - coral reefs were originally thought to be "nutrient deserts".

So it would make sense that many have experienced better overall coral health by letting mineralized nutrients run much higher than typical ocean water values because corals are heterotrophic, and can potentially adapt from one source of nutrients to another to some degree.

 

[Reefin' Dude]

i am not sure this is anything new. the differences between what nutrients are inorganic and what is organically bound does not seem to be explained to reefers and leads to a lot of the confusion about what is going on in our systems. we all seem to want to consider the nutrients all the same, yet when we test, we are only able to test for inorganic, missing an entire group of nutrients. when it is discussed that the reefs are "nutrient deserts" it is the inorganic nutrients that are in very short supply. the organically bound nutrients are available in the various planktonic media.

the problem comes from what is necessary to feed the organisms that can "create" this organically bound nutrients that the corals will feed on. the inorganic nutrients. do we really need to be fueling an entire food chain of biomass (which in itself indicates an increase in total nutrients of a system) when we can feed the corals we want to keep directly?

G~

 

[dkeller_nc]

the problem comes from what is necessary to feed the organisms that can "create" this organically bound nutrients that the corals will feed on. the inorganic nutrients. do we really need to be fueling an entire food chain of biomass (which in itself indicates an increase in total nutrients of a system) when we can feed the corals we want to keep directly?

Personally, I think that's just a difference in philosophy, and most of us do both, whether intentionally or otherwise. In theory, products like Oyster Feast can completely substitute for the ocean's zooplanktonic food chain, but in practice, I have my doubts. If you've ever dove on a coral reef at night, the water is absolutely filled with all manner of planktonic life of all sizes and descriptions for many hours. I think that would be exceptionally difficult to reproduce adequately in a completely closed environment like a reef tank.

But that doesn't keep me from trying - I dose my tank after lights out every night with phytoplankton to encourage zooplanktonic life, and in theory that's the purpose of a refugium as well. But I can't deny that many people successfully keep what I call a "coral garden", where feeding of zooplanktonic substances is minimal and the water is kept scrupulously clean and free of inorganic nutrients. Many of these systems are spectacular to look at, and they grow coral very well.

But there are some of us that are just as interested in supporting more of the huge diversity of life on a reef, such as sponges, tunicates, foraminifera, crinoids, non-photosynthetic mollusks, corals and other animals, and the like. I don't know if that will ever be possible, but it seems like a laudable goal...

 

[Reefin' Dude]

that is great for those corals and organisms that can live in that trophic environment. with what you are saying there will still need to have a large amount of inorganic nutrients available to feed the organisms that are "going to feed" the corals. some corals have adapted to not be exposed to that amount of available inorganic nutrients. they have evolved to live there for a reason.

all of those organisms you listed do not necessarily live on the same reef. we all want to think that all of the organisms we can acquire can all live together.most do not in the wild, so why should we think that we can do it in our reefs easily?

it is all about creating a system to the environment for the "must have" organism. it may be oligotrophic, it may be eutrophic, it may be mesotrophic.

i think our tanks are far from closed. they may be closed in respect to higher organisms, but they are not closed with respect to just about everything else, whether it is water, oxygen, nitrogen, carbon, bacteria, and even phosphates if a skimmer is employed. we may want to think of them as closed, but by the true definition they are not. if one would like to say closed with respect to higher organisms, that would make sense. matter is constantly being transferred into and out of the system through gas exchange, water evaporation, and even skimming.

G~

 

[dkeller_nc]

Don't get me wrong - my tank is very far from eutrophic. I do go to the standard efforts to keep dissolved organic matter and mineralized nutrients to a minimum. Typical mineralized nutrient values are very near the detection limit of the tests, though presumably they are not zero. The idea is to keep mineralized nutrients to a minimum and nutrients in the form of small micro and macroscopic creatures available.

This is quite different than the goal when I started this addiction in the early 1990's. At that time, very few deliberately fed their corals anything other than the microscopic life that the tank would generate on its own.

As you pointed out, there's no-one-size-fits-all for water conditions that will generate success for all of the corals we'd like to keep, and the general philosophy present in the early 1990's is pretty good evidence of that. Certain types of photosynthetes were pretty easy to keep and grow, but some of them were virtually impossible - goniopora is probably the best know example.

 

[elegance coral]

There's only one difficulty with this analogy (though I certainly understand the logic). Coral reefs are not so nutrient poor as has been previously assumed. Yes, it is very true that the seawater around them is extremely low in dissolved, mineralized nutrients such as PO4 and NO3.

But overall, they are bathed in a nutrient bath of zooplankton and phytoplankton, which is not something that we can currently reproduce in our tanks. The extent of this wasn't recognized until very recently - coral reefs were originally thought to be "nutrient deserts".

So it would make sense that many have experienced better overall coral health by letting mineralized nutrients run much higher than typical ocean water values because corals are heterotrophic, and can potentially adapt from one source of nutrients to another to some degree.

http://www.reefcentral.com/forums/showthread.php?t=2089061&highlight=ecosystems

I know it's a long thread, but it would probably be worth while for you to read it. If you don't have the time, check out post number 98, on page 4.

It would be very, very difficult for you to retain your beliefs after reading the above thread.

Peace
EC

 

[SantaMonica]

goniopora is probably the best know example

Wouldn't you know, that one was one of my favorite long-term successes of the time.

 

[TankStudy]

If I'm understanding this correctly we want organic phosphates but not inorganic phosphates. I've read posts of people saying zooanthids/palythoas need some amount of phosphates and people always put a reference range of what they believe is good. Do zooanthids/palythoas use the inogranic phosphates too then or are people mistaking the organic phosphates which is not measurable, if I'm not mistaken, with the inogranic phosphate?

Any input would be greatly appreciated. I've gone thru a few pages of the posts and most deal with SPS, I'd like to know about the relationship between zoas/palys and phosphates as well.

 

[SantaMonica]

All photosynthetic corals make "organic" phosphate from inorganic phosphate. The organic is glucose, and it is partially consumed by the coral, and partially released into the water to feed microbial laters, which are also consumed by the coral.

My favorite organic phosphate, however, is peanut butter

 

[MHG]

A very interesting reed. Someone mentioned on page 5 about someone with stable parameters varying alkalinity for a few weeks to see what happened with the colors. I messed around with several things in my tank for two years. Searching for a clue to why frags would lose color and some would die within a couple of weeks. First I messed with light. Having access to a par meter, I found I was cooking them at 900 par... Lowering the light did not help...some palys responded well to lower light but not sps. Messing with alk levels did nothing as well. Too high i get rtn. To low i get rtn. Keeping them between 6-8 and no issues...Zero to no growth on all sps (except my purple stylo and green birdsnest)...I thought it could not possible be low nutrients because of all the great tanks out there with zero nutrients...

After about a year and a half with no growth... I mean NO growth...like the same 10 heads of zoas and a tank full of frags, I decided to feed heavily and get my nitrates up. Within a few weeks zoa heads were popping up, and frag plugs were getting encrusted. Within 3 months I was fragging some corals to keep them from touching. Within 6 months I frag monthly... Colors came back on 90% of my corals within 7 months...

 

[thabizness]

A couple of questions MHG cause I am going thru the same thing with very little growth. I test 0 Nitrates and 0 Phosphates and have started to feed more heavily mainly reef chilli, and frozen to my nems. I feed my fish pellets daily. I have went from 10 gallons every week to 10 gallons every two weeks. This is all an attempt to start detecting nitrates and phosphates. I do grow chaeto with other algae in the sump.

How much more did you feed? What was the par values for the zoas? Did you have any other forms of nutrient export? Skimmer?

Biz

A very interesting reed. Someone mentioned on page 5 about someone with stable parameters varying alkalinity for a few weeks to see what happened with the colors. I messed around with several things in my tank for two years. Searching for a clue to why frags would lose color and some would die within a couple of weeks. First I messed with light. Having access to a par meter, I found I was cooking them at 900 par... Lowering the light did not help...some palys responded well to lower light but not sps. Messing with alk levels did nothing as well. Too high i get rtn. To low i get rtn. Keeping them between 6-8 and no issues...Zero to no growth on all sps (except my purple stylo and green birdsnest)...I thought it could not possible be low nutrients because of all the great tanks out there with zero nutrients...

After about a year and a half with no growth... I mean NO growth...like the same 10 heads of zoas and a tank full of frags, I decided to feed heavily and get my nitrates up. Within a few weeks zoa heads were popping up, and frag plugs were getting encrusted. Within 3 months I was fragging some corals to keep them from touching. Within 6 months I frag monthly... Colors came back on 90% of my corals within 7 months...

 

[Reefin' Dude]

After about a year and a half with no growth... I mean NO growth...like the same 10 heads of zoas and a tank full of frags, I decided to feed heavily and get my nitrates up. Within a few weeks zoa heads were popping up, and frag plugs were getting encrusted. Within 3 months I was fragging some corals to keep them from touching. Within 6 months I frag monthly... Colors came back on 90% of my corals within 7 months...

more reefer logic. corals need an initial source of organic N and P. we have been "told" by some that waste products of algae will provide this to our corals, not completely the case. corals need to be fed heavily, only those that are worried about nutrients will tell you otherwise. the bigger question is what is going on with waste products from all of that feeding. the corals have developed a symbiotic relationship with the algae/bacteria within them. they tightly recycle N and P amongst themselves, but there still needs to be constant input of new N and P for the corals to get the process started and bring in new building materials. the reason being is because readily available inorganic N, P, and CO2 are not readily available on a healthy oligotrophic reef. if it was, then the algae/bacteria would not need to live inside the coral.

G~

 

[SantaMonica]

I decided to feed heavily

Yes corals do need lots of food particles to grow. The trick is how to feed them while controlling nitrate and phosphate at the same time. (Hint: skimmers remove food particles).

Somewhere on RC is a big thread on feeding your corals so they will grow.

 

[kc350twin]

Really great thread. I've been struggling with sps colors for a bit now and this topic hits home.