Nitrates in an SPS Tank

[ShaunW]

The coral colors you see are a defensive measure. The corals fluoresce/reflect light that is harmful or unused by the zoox. The coral only needs a certain amount of photosynthesis and will limit the light the zoox receive or expel them when getting to much. The zoox enable the coral to make amino acids by providing it with a photosynthate. After the zoox are limited the coral still needs to get amino acids from somewhere or they "starve". To prevent this I'll dose AA's directly, unlike the indirect way of feeding fish. Basically its changing the way they eat to improve colors. Don't know if I will be successful but I would like to try.

There are a lot of topics that you bring up here, , that I have wondered about for sometime.

My questions on this paragraph, (to which I have my own thoughts) that I would like to know answers to are:
1. Some SPS can generate all their amino acid requirements from photosynthesis, so I am assuming your talking about the species that cannot do this, . Yes?
2. When and under what conditions would the zoox becomes limited? and once this occurs the idea of coral starvation needs to be better defined. Since slow growth or stagnation is another possiblity, but I am sure is an occurrence that we only observe in corals that are not in the wild. Therefore the idea of coral starvation is not a "normal" biological occurrence for corals.
3. What amino acids are being dosed and in what concentration? To know this is very important, i.e. essential vs. non-essential, L vs. D form.
4. What direct uptake systems do SPS corals have to sequester amino acids directly? I would think that algae and bacteria would be much more efficient in amino acid uptake mechanisms, i.e. so how does dosing to the whole tank ensure that the corals get the "goodies"?
5. If bacteria use up the dosed amino acids, which is a very real possibility, then from their subsequent growth spurt how do you know that you are just not creating another molecule to become limiting in the tank due to this utilization of nutrients, i.e. iron for example. Thus preventing "bad" algae to grow and additionally providing food for the SPS in the form of bacterioplankton.

 

[ShaunW]

BTW Paul, correct me if I am wrong but the tank that you gave the link to on RC, it seems that his corals are becoming more and more faded with time. While they are colorful they seem much more lighter than a year ago. Is this true?

 

[kimoyo]

again, not to sidetrack the thread, but...
A) the colors, you theorize, is in essence a sun-block or UV protection.

This is proven.

so why is there a need to supplement amino acids if (B) the zoox are providing it and (A) the zoox are only limited once they are producing excess?
and why would supplementing amino acids (B) improve color, if color (A) is only a response/defense against lighting?

Zoox has two pigments in a 4 to 1 ratio and they combine to look brown. What some try to do is limit this brown color as much as possible to get to the corals colors. I've listed this on MR before but I'll put it up here. This is a quote from Mike (Mojoreef) but I've seen some of these numbers in papers also.

>Pocilloporin primarily absorbs green/yellow (550-600 nm) light along with some upper UV-A . it emmits a orange/red
>highly fluorescent pocilloporins primarily absorbs light from 310 to 380 nm (UV-B and UV-A) and then fluoresces this as light from 400 to 470 nm (violet/blue).
>highly fluorescent pocilloporin primarily absorbs light from 380 to 470 nm (UV-A, violet and blue) and fluoresces light from 475 to 520 nm (blue and green).
>third type of highly fluorescent pocilloporin primarily absorbs light from 430 to 490 nm (violet and blue) and fluoresces light from 490 to 540 nm (green/yellow).
>Yellow fluorescing pocilloporin primarily absorbs light from 440 to 500 nm (blue) and fluoresces light from 520 to 620 nm (green, yellow and orange).
>Red/Orange Fluorescing pocilloporin that primarily absorbs light from 500 to 540 nm (green) and fluoresces light with wavelengths that are primarily orange to red.

These are some wavelengths that will be flouresced by corals at different wavelengths.

But once you limit the zoox you still need to provide the coral with the amino acids that use to be gained as a result of the photosynthesis of the zoox. So you dose the AA's directly. Its a similar concept to when hobbyist feed heavily (coral food) and lower their photoperiod (limit zoox loss).

For the recorrd, i do not claim to know what i'm talking about, just asking questions based on what you explained.

None of those comments were specifically directed at you. Sorry if it came out that way. I just didn't want to argue with anyone on MR anymore. I can deal with RC but I don't want to do that here.

 

[kimoyo]

1. Some SPS can generate all their amino acid requirements from photosynthesis, so I am assuming your talking about the species that cannot do this, . Yes?

No I believe this would apply to any species because the idea is to limit photosynthesis.

2. When and under what conditions would the zoox becomes limited? and once this occurs the idea of coral starvation needs to be better defined. Since slow growth or stagnation is another possiblity, but I am sure is an occurrence that we only observe in corals that are not in the wild. Therefore the idea of coral starvation is not a "normal" biological occurrence for corals.

You could probably answer that first question better than me . Nutrient poor and light intense. Whether or not its nitrate or phosphate or something else I don't know. I was just going to try to get nitrates and phosphates down as low as I could, then give the corals a lot of light so they expel the zoox or block light from them.

Inhibiting photosynthesis can lead to calcification inhibition but since we're trying to get lower zoox population by doing this it probably won't be a problem if we are successful. By lowering the zoox population the coral won't have to compete for a carbon source.

3. What amino acids are being dosed and in what concentration? To know this is very important, i.e. essential vs. non-essential, L vs. D form.

I have no idea nor do I know what that means :lol2:. I was just going to try the prodibo. Maybe you could do a test, if you had the time, and figure it out.

4. What direct uptake systems do SPS corals have to sequester amino acids directly? I would think that algae and bacteria would be much more efficient in amino acid uptake mechanisms, i.e. so how does dosing to the whole tank ensure that the corals get the "goodies"?

Studies have shown that they do infact uptake amino acids directly from the water. There is a paper from 1990 but I'm at work and don't have the reference. I believe it was a paper more about ocean reefs so it wasn't really an issue because amino acids aren't readily availalbe in the ocean.

5. If bacteria use up the dosed amino acids, which is a very real possibility, then from their subsequent growth spurt how do you know that you are just not creating another molecule to become limiting in the tank due to this utilization of nutrients, i.e. iron for example. Thus preventing "bad" algae to grow and additionally providing food for the SPS in the form of bacterioplankton.

Have no clue. Actually this is something I would ask you. Are there certain amino acids that the bacteria won't consume? Is that possibly what the prodibo AA are? But they do sell separate bacteria food and coral food (AA).

 

[kimoyo]

BTW Paul, correct me if I am wrong but the tank that you gave the link to on RC, it seems that his corals are becoming more and more faded with time. While they are colorful they seem much more lighter than a year ago. Is this true?

He changed cameras and thats why they look different is what he said.

 

[alrha]

wait, now i'm confused again...

are you trying to 'blast' light to get the coral to expel some zoox, but make up for their lost production by providing amino acids, under the assumption that less zoox will yield less brown and more color?

p.s. no offense taken to anything, i just wanted to be clear as i try to participate a bit that i am not speaking out of any particular knowledge on this topic, but rather am just trying to understand what i'm reading.

 

[kimoyo]

wait, now i'm confused again...

are you trying to 'blast' light to get the coral to expel some zoox, but make up for their lost production by providing amino acids, under the assumption that less zoox will yield less brown and more color?

Yep, that pretty much sums it up but its also to try to get the coral's pigments to grow.

The guy Iwan has seen some serious growth and I've also been wondering if the low zoox population, which leads to less competition for Carbon, has help that growth.

 

[alrha]

Yep, that pretty much sums it up but its also to try to get the coral's pigments to grow.

cool, i got it. until now...
how does pigment grow? did you mean to 'reveal' the masked pigment? or did you mean to get the coral to grow?

 

[Ebby]

Yep, that pretty much sums it up but its also to try to get the coral's pigments to grow.

The guy Iwan has seen some serious growth and I've also been wondering if the low zoox population, which leads to less competition for Carbon, has help that growth.

why do you think that by "blasting" light the zoox will be expelled? is this a fact? and then, corals and zoox are symbiotics so they're not really competing for anything.

 

[kimoyo]

why do you think that by "blasting" light the zoox will be expelled? is this a fact? and then, corals and zoox are symbiotics so they're not really competing for anything.

Corals and zoox are symbiotes but in the situation of high light intensity (increased photosynthesis) or excess zoox, the coral may be unable to keep up with C demand. At that point the zoox can outcompete the coral for a carbon source.

I think "blasting" the coral will lead to a lose of zoox but it doesn't have to be expelled. An extreme case of zoox loss would be bleaching of which excess light is one of its causes.

 

[Ebby]

Corals and zoox are symbiotes but in the situation of high light intensity (increased photosynthesis) or excess zoox, the coral may be unable to keep up with C demand. At that point the zoox can outcompete the coral for a carbon source.

I think "blasting" the coral will lead to a lose of zoox but it doesn't have to be expelled. An extreme case of zoox loss would be bleaching of which excess light is one of its causes.

i kind of see where you're going, but i don't necessarily agree with you.
Zooxanthellae are photoautotrophic dinoflagellates. so they obtain their energy requirements through photosythesis and carbon through CO2 (which they get from the coral due to respiration).

Through permeases, the zooxanthellae can transport as much as 98%
of it's photosynthetic byproducts through its plasma membrane to the coral.
In this manner, corals are able to obtain the necessary components
for their sustenance and growth such as amino acids, fatty acids, and carbohydrates from the zooxanthellae.

Likewise, zooxanthellae require certain components to carry on
photosynthesis. Aside from protection from predation, the zooxanthellae's
other main benefit is that it gathers necessary ingredients to carry on it's photosynthesis and growth.
so as far as i know, CO2 removal by zooxanthellae is hypothesized as the primary event responsible for increased growth in corals containing zooxanthellae. and also zooxanthellae actively remove phosphate from within and surrounding the coral, then calcification is enhanced,
and corals, by theory and through observation, grow at increased rates.
so my point is ( i do really have a point after all this) that i don't understand why you're trying to reduce the zoox population..and we should not forget that by increasing the lighting the coral may suffer from superoxidation within its tissue if exposed to too much light due to zooxanthellae "overproduction".

 

[spykes]

ebby, your so cool i wanna be like you =D

 

[kimoyo]

i kind of see where you're going, but i don't necessarily agree with you.
Zooxanthellae are photoautotrophic dinoflagellates. so they obtain their energy requirements through photosythesis and carbon through CO2 (which they get from the coral due to respiration).

Through permeases, the zooxanthellae can transport as much as 98%
of it's photosynthetic byproducts through its plasma membrane to the coral.
In this manner, corals are able to obtain the necessary components
for their sustenance and growth such as amino acids, fatty acids, and carbohydrates from the zooxanthellae.

Likewise, zooxanthellae require certain components to carry on
photosynthesis. Aside from protection from predation, the zooxanthellae's
other main benefit is that it gathers necessary ingredients to carry on it's photosynthesis and growth.
so as far as i know, CO2 removal by zooxanthellae is hypothesized as the primary event responsible for increased growth in corals containing zooxanthellae. and also zooxanthellae actively remove phosphate from within and surrounding the coral, then calcification is enhanced,
and corals, by theory and through observation, grow at increased rates.
so my point is ( i do really have a point after all this) that i don't understand why you're trying to reduce the zoox population.

At high light intensities and large zoox populations there's a point where the coral can't keep up with the demands of photosynthesis for CO2 (carbon source). What happens then? The zoox start drawing directly on the carbonate/bicarbonate entering the coral severely inhibiting calcification/skeletogenesis, almost halting growth and possibly leading to the death of the coral.

Dr. Szmant talked about this in her lectures and I know of several research papers that support this. Look up Marubini & Atkinson 1999, "Effects of lowered pH and elevated nitrate on coral calcification", they did a study showing exactly this.

.and we should not forget that by increasing the lighting the coral may suffer from superoxidation within its tissue if exposed to too much light due to zooxanthellae "overproduction".

Sounds like you understand this pretty well and probably better than me . So you know that "blasting" the corals can cause oxidative stress, which leads to super oxide radicals and peroxide, which cause zoox breakdown (loss). This is one of the forms of zoox loss I was referring to.

 

[kimoyo]

Likewise, zooxanthellae require certain components to carry on photosynthesis. Aside from protection from predation, the zooxanthellae's
other main benefit is that it gathers necessary ingredients to carry on it's photosynthesis and growth.

Can you explain this more, how does the zoox protect the coral from predation and how/what are they gathering?

 

[Deanos]

Can you explain this more, how does the zoox protect the coral from predation

She means the zoox is protected by the coral from predation.

 

[ShaunW]

At high light intensities and large zoox populations there's a point where the coral can't keep up with the demands of photosynthesis for CO2 (carbon source). What happens then? The zoox start drawing directly on the carbonate/bicarbonate entering the coral severely inhibiting calcification/skeletogenesis, almost halting growth and possibly leading to the death of the coral.

Then why would you want to actively strive for this to occur?

But before it goes to an extreme I would think that the coral would either expell the zoox or limit their growth by limiting a nutrient given to them.

 

[ShaunW]

I know that the goal of all this it to have good growth and intense color, however, trying to achieve these goals by keeping the coral on the border between life and death is walking a very fine line in my opinion.

Also by limiting the zoox population your removing a large P and N sink from the system. Adding amino acids would take away from the zoox's job in vivo, but I still think that other organisms within the tank are going to utilize the dosed amino acids more efficiently and quicker than the intended target (SPS).

 

[kimoyo]

Then why would you want to actively strive for this to occur?

We don't want that occur! Thats we try to keep the corals in a nutrient limited (nitrates and/or phosphate) system.

But before it goes to an extreme I would think that the coral would either expell the zoox or limit their growth by limiting a nutrient given to them.

Like we were talking about last month, I don't know if the coral can limit the nutrient supply to the zoox.

 

[kimoyo]

I know that the goal of all this it to have good growth and intense color, however, trying to achieve these goals by keeping the coral on the border between life and death is walking a very fine line in my opinion.

I'm not sure this is walking the line between life or death; its not about bleaching the coral. Using Dave's early analogy, we all need fat but too much isn't a good thing. All your doing is giving the coral a good amount (not an extreme amount) of good light, trying to create a very low nutrient system and dosing amino acids. Except for the dosing amino acids, most hobbyist try to do this anyway.

Adding amino acids would take away from the zoox's job in vivo, but I still think that other organisms within the tank are going to utilize the dosed amino acids more efficiently and quicker than the intended target (SPS).

I've asked Iwans' thoughts about this.

 

[ShaunW]

Paul, it will be interesting to see if it works, . Personally, I'm more of a purist at heart, i.e. keeping the system simpler than more complex. For me, BB, with monthly 1/3 tank water changes and an efficient skimmer works well. Normal amounts of lighting and daily feeding of different foods. I gave up on adding supplements years ago, the cost/reward ratio was too high to justify.

BTW, how much light are you actually talking about anyway? 2 400watt MH over a 30 gallon tank? or something much less?

Doesn't Iwan use T5's (but I may be wrong)?