High nitrate cause brown-out ?

[kysard1]

Originally posted by MCsaxmaster
Kurt,

I would suggest that light and waterflow need to be focuses to keep most any reef animals. .

cj

My tank is 30x18x21".

Waterflow : Vortech and a closed loop.
Light : 250W 10k Ushio with the SPS in the top 1/3 directly under the bulb.

I have a hard time thinking that lack of waterflow and lighting caused these corals to brown.

I like scientific hypothesis just as much as the next guy. But we need empiricism folks. These theories are nothing more than science fiction without experiements and data from reef aquaria.

How about some real life accounts ?

[MCsaxmaster]

I like scientific hypthesis just as much as the next guy. But you have we need empiricism folks. These theories are nothing more than science fiction without experiements and data.

How about some real life accounts ?

Where do you think I got this information?

[kysard1]

Its good stuff, just that it goes against the last decade of practical reefkeeping husbandry. Hard to swallow.

But I have an open mind

Should we toss our DI filters?, certainly 10 ppm TDS is good enough?

Unfortunately doesn't answer why my frags turned brown.

[fijiblue]

I like scientific hypthesis just as much as the next guy. But we need empiricism folks. These theories are nothing more than science fiction without experiements and data from reef aquaria.

I agree. I think this thread lost it's value a while back. Dead end road

[kysard1]

Originally posted by fijiblue
I agree. I think this thread lost it's value a while back. Dead end road

I wouldn't go that far, the thread just needs to be a little more pragmatic.

[MCsaxmaster]

Originally posted by kysard1
Its good stuff, just that it goes against the last decade of practical reefkeeping husbandry. Hard to swallow.

But I have an open mind

Should we toss our DI filters?, certainly 10 ppm TDS is good enough?

Unfortunately doesn't answer why my frags turned brown.

What "goes against the last decade of practical reefkeeping husbandry?"

As I've attempted to illustrate, elevated nutrients may lead to brownish looking corals due to increased zoox. pigment density, but this is not requisite with elevated nutrients because many factors also figure into the extent to which corals produce their own colorful pigments.

We know that dissolved N and light intensity are two factors that do work to determine coral coloration. They most certainly aren't the only factors though, but we haven't even begun to characterize other factors.

I can't tell you why your corals turned brown. No one can, and pretending that we could pinpoint the reason is unrealistic at best, and delusional at worst.

cj

[kysard1]

Originally posted by MCsaxmaster
What "goes against the last decade of practical reefkeeping husbandry?"


I can't tell you why your corals turned brown. No one can, and pretending that we could pinpoint the reason is unrealistic at best, and delusional at worst.

cj

So at this point SPS are a crap shoot.

I don't even like casinos.

[MCsaxmaster]

I'd perhaps consider things this way:

If corals are very colorful (pretty) when they are collected then this coloration is the response to a set of environmental conditions. All of needs for the basic biology of the animal are taken care of by virtue of the fact that it is living in the environment in which it has evolved to live. The major factors controlling coloration for at least a lot of the nicely colored corals out there are: 1. the genes needed to code for the proteins and produce them in large amounts (many/most corals either don't produce these colorful proteins, or don't produce large quantities of them), and 2. light intensity.

When we come to captivity we have a more complicated situation. If we buy a coral that was colorful at some point we know that it has the "right" genes. We do have to worry about light intensity now, and just getting a coral in captivity we have no idea where exactly it was originally located and what kind of light intensity allowed the induction of the particular pigment or set of pigments we are interested in.

In captivity we also have to worry about providing for all kinds of needs just for the basic biology of the animals (clean water, sufficient waterflow, sufficient food, etc.). In nature these are just sort of 'taken care of' naturally so we needn't consider them too terribly much in natural assemblages, but if the basic biology of the animals is not satisfied in captivity then all sorts of processes (like producing colored proteins) might get screwed up.

So, in captivity we have to experiment to figure out what sorts of conditions are required to induce the corals to produce the same kinds of pigments as they did in nature and to similar densities. Providing for the basic needs of the animals--covering the basic biology--is a bit of a prerequisite to achieve this, but is not entirely simple as this means achieving acceptable parameters in several areas of husbandry. Once we have achieved this we need to, at the very least, figure out what kind of light intensity is appropriate to induce the production of the pigments of interest in the corals.

It is all a matter of figuring out how to do a sufficient job of providing for the needs of the corals as well as sufficiently replicating the lighting necessary to induce the corals to produce some suite of pigments.

cj

[mntl]

THIS Is a test on the effects of lowered ph (8 to 7.2 in this case, which interestingly cut growth almost in half!) and increasing nitrate through the use of kno3. The ph seemed to have an effect, but the nitrate had little to none (they were testing calcification rates). They did mention zooxanthellae density, mentioning that in a past study 5-20um no3 increased zoox density and decreased calcification, the increased zoox resulted in what was described as "much darker corals than those grown in open waters". Thsi study however did not show any change, even after 7 weeks of increased levels. The levels used were not as high as the previous study however.

Not much help i know, but something to read if interested in no3 addition to your tank.

-John

[mntl]

Marubini F, Davies PS (1996) Nitrate increases zooxanthellae population density

This is the other paper mentioned in the article listed above (incase someone wants to look into it), i can not seem to find a link to the full paper. If you look into what other more "well know" reefkeepers/authors list as their source for the info they give on what nitrate does to acros, this is the paper listed in every instance i have seen so far. I am having problems finding any other reference to any papers that studied only nitrate effects and not simply "runoff" or "pollution"? There are many papers listing phosphate as being harmful, but they do not seem to mention that it increases zoox densities in acros?

Anyone else have any more links?

-John

[mntl]

Dbl post

[jmaneyapanda]

Originally posted by kysard1
My tank is 30x18x21".

Waterflow : Vortech and a closed loop.
Light : 250W 10k Ushio with the SPS in the top 1/3 directly under the bulb.

I have a hard time thinking that lack of waterflow and lighting caused these corals to brown.

I like scientific hypothesis just as much as the next guy. But we need empiricism folks. These theories are nothing more than science fiction without experiements and data from reef aquaria.

How about some real life accounts ?

HA! No offense, but this is what I have been begging for this entire thread. And the only posters who have said said anything but speculation have been Mntl and MCsax.

Using your own mantra here, where is the empirical evidence that it is nutrients that cuase the colors to brown? Mntl has provided some borderline empirical work, but this is just as speculative as you are calling out other theories to be.

[acrylic_300]

A lot of times during shipping corals brown out or if you lose a frag between the rocks for even a couple days it will brown out.

What about the lighting schedule? I think the schedule of lighting has a lot to do with bleaching and brownout also.

If you could raise nutrients without changing water clarity would it even make a difference?

[fijiblue]

Here is a theory on the browning during shipping. The coral gets bagged in oxygen rich water (hopefully) . During shippment, it is dark which means the cellular respiration is taking place. Since the coral is in a small bag of water, the oxygen is depleated rather quickly and CO2 levels begin to rise. Since there is no light then to convert the CO2 into sugars through photosynthesis, the coral has to directly absorb these carbon sources. Since this would affect the zoox department, the reproduction increases to utilize the energy...aside from any die off that would increase waste levels and further increase zoox population.

Just one of many I can come up with.

[acrylic_300]

Originally posted by fijiblue
Here is a theory on the browning during shipping. The coral gets bagged in oxygen rich water (hopefully) . During shippment, it is dark which means the cellular respiration is taking place. Since the coral is in a small bag of water, the oxygen is depleated rather quickly and CO2 levels begin to rise. Since there is no light then to convert the CO2 into sugars through photosynthesis, the coral has to directly absorb these carbon sources. Since this would affect the zoox department, the reproduction increases to utilize the energy...aside from any die off that would increase waste levels and further increase zoox population.

Just one of many I can come up with.

So anytime zoox is not happy with the intensity of lighting it would do this? Some sort of survival mode?

Makes sense since zoox usually gets expelled with higher light.

Seems odd that zoox can reproduce faster without photosynthesis though.

[MCsaxmaster]

Originally posted by fijiblue
Here is a theory on the browning during shipping. The coral gets bagged in oxygen rich water (hopefully) . During shippment, it is dark which means the cellular respiration is taking place. Since the coral is in a small bag of water, the oxygen is depleated rather quickly and CO2 levels begin to rise. Since there is no light then to convert the CO2 into sugars through photosynthesis, the coral has to directly absorb these carbon sources. Since this would affect the zoox department, the reproduction increases to utilize the energy...aside from any die off that would increase waste levels and further increase zoox population.

Just one of many I can come up with.

I don't want to come off as a jerk, but that is nowhere close to physically possible.

The corals cannot do anything with CO2. The zoox. can fix CO2 in the presense of light (or shortly after having been exposed to light), but without the chemical potential energy produced in the cell that is gained by initially capturing light, the zoox. can't do anything with CO2.

Seems odd that zoox can reproduce faster without photosynthesis though.

Only because it's not possible

cj

[fijiblue]

I don't want to come off as a jerk

It's ok...you did that a while ago

[MCsaxmaster]

Ha, jeez

[twon8]

Originally posted by fijiblue
It's ok...you did that a while ago

a bit uncalled for imo.


kysard- perhaps you have too much light on your tank, and your corals are browning to prevent being burned, you've given them too much of a tan.

good colors come from a healthy tank, how to get to a healthy tank is the key, and there are many ways there.

[MCsaxmaster]

Originally posted by twon8
a bit uncalled for imo.

I assume fijiblue was just kidding...at least I hope so

[kysard1]

Originally posted by twon8
a bit uncalled for imo.


kysard- perhaps you have too much light on your tank, and your corals are browning to prevent being burned, you've given them too much of a tan.

.

I don't know if you are serious, but I do notice not many using a 10K 120 PAR bulb over a 20" deep tank. Most are using 14k bulbs with half the PAR.

[fijiblue]

Of course I was kidding hence the smiley face!

[MCsaxmaster]

No worries

[stony_corals]

GD! There are three new posts that just popped up asking how to make their sps colors pop....

Can a mod sticky this?

Thanks everyone for their contribution, one of the best threads in a while...

[RiddleLabs]

Aloha all,

Just a quick note from the trenches in sunny Hawaii...

Re: Nutrient loading and coloration. Hawaiian waters (nearshore on the Big Island) aren't the proverbial 'nutrient desert'. Nitrates (due to leaching from volcanic rock) and phosphorus (likely from the cesspools of hundreds of homes lining the coast) are realtively high when compared to the low nutrient measurments from oceanic waters. Yet, there are beautiful blue Montipora flabellatas, blue/red polyped Monitora patulas, red Pocillopora spp., occasional blood red Cyphastraea, purple Porites lutea and any number of green corals.
If nutrients were the only cause of 'browning', we would never see a colorful polyp - they would be brown from all the nutrients from digested food in the gastrovascular cavity.