It's Still in the Water!

cfockler

New member
Dr. Ron,
I just read your "in the water" articles and have to admit that my mouth is hanging open a bit at the moment. I think the article said that the test kit I paid for and have used sporadically from time to time is basically not needed. And there was a comment about additives not being needed. Is that correct? Are test kits and dosing to be added to the old-school-don't-do-that-anymore pile (along with wet/dry filters, plenums, substrate-less tanks, and soon enough skimmers) ???

Are you saying I don't need to worry about using the test kits anymore? I don't need to worry about dosing to keep up calcium levels? Can I do away with the Kalkwasser?

This would be very nice, but seems to good to be true. Did I misinterpret your words?

:confused:
 
Hi Chris,

Well, you may use the Calcium test kit and with some luck it may give reasonable results.

With regard to additives - take a look at the next month's article (due out in about 2 weeks).

Levels of some trace elements, specifically nickel, copper, zinc and vanadium are well into the lethal range as it stands in our tanks, and we are losing or stressing animals because of this.

As regards other additives - you need to add calcium and maintain the proper alkalinity, other than that not only are no other additive necessary, but most of them are probably cumulative poisons.

Enjoy... :D
 
That's great news and also bit surprising. I find it unbelievable that other "experts in the field" have never performed water quality test until know. Surely the companies that are selling these additives did similar tests to determine what elements to add to their product and in what quantities. Surely the people who have advocated regular dosing of these elements have some kind of chemical anaylsis to back their methods!?!?

Why is this information just now being revealed? Has this been a big scam and coverup all along?

Thanks , Dr. Ron, for bringing the facts to us lowly hobbyists.
 
Originally posted by cfockler
Hi,

That's great news and also bit surprising. I find it unbelievable that other "experts in the field" have never performed water quality test until know.

Well, most of them haven't. These water quality projects have cost a cumulative total of over $10,000, so most "experts" haven't done a thing. Most of them, as well, have no understanding of animal physiology.

Surely the companies that are selling these additives did similar tests to determine what elements to add to their product and in what quantities.

I doubt it. I think they just developed something that has a weak solution of numerous - or few - trace elements and sold it.

Surely the people who have advocated regular dosing of these elements have some kind of chemical anaylsis to back their methods!?!?

Some of them may have, but if so, it is not published. Also they seem to have ignored the scientific literature on the effects of such materials - particularly in the pollution literature.

Why is this information just now being revealed?

I guess, because I am finally getting some projects done and because [rk] will publish it. Some of the print magazines have published an article or two (I had an article in FAMA last winter on "Toxic Trace Elements") but others, such as TFH, were afraid to publish such articles for fear of offending their advertisers.

Has this been a big scam and coverup all along?

More just a confederation of ignorance.
 
thanks for making the new issue article on toxicity readable. i appreciate the time and effort it took to produce.
 
Ron,

FWIW, I'm not entirely sure how applicable the LD50 results are within a marine aquarium. For example (via the last ICP test I had run, I have another batch in for testing ATM) I have 211ppm Cu and 212ppm Pb. How visibily would you expect this to affect the growth of my mainly SPS corals? Although I am taking measures to remedy these high levels (something like x100,000 NSW IIRC) I am still getting approx .5-1.5cm growth per week of my Acropora depending on species. I also have had an A. millepora spawn recently.

This is not to say that one should be blaise about the micronutrient elements, merely that I do question the applicability of some of the papers you have quoted within our particular sphere of interest. For the minute I'll stick with my feed heavily and water 50% every 3-4 months (note: I suspect that this water change regime does somewhat support your assertions).

Your thoughts?
 
Last edited:
Originally posted by andy-hipkiss

Hi,

FWIW, I'm not entirely sure how applicable the LC50 results are within a marine aquarium. For example (via the last ICP test I had run, I have another batch in for testing ATM) I have 211ppm Cu and 212ppm Pb. How visibily would you expect this to affect the growth of my mainly SPS corals?

More than likely, you - and most of us - have morphologies or species of corals that are pollution tolerant growing in our systems; in effect, they would have to be to survive. Such corals are found in nature, as well - but are not normally dominant as they generally grow slower and compete less well than their non-tolerant cousins. These animals likely be able to detoxify additional amounts of the toxic chemicals.

I would expect that such animals would grow and spawn, although I would expect that the survival of the the offspring would be signficantly lower than what one would find in natural situations.

Additionally, in some - maybe most - tanks, bacterial and algal byproducts may be producing compounds that help bind the toxic metals, and in these cases growth could appear quite normal until some threshold is reached and then the tank could start to experience products. This would be the onset of the "old-tank" syndrome. So... I suspect your system is, in effect, a time-bomb.

This is not to say that one should be blaise about the micronutrient elements, merely that I do question the applicability of some of the papers you have quoted within our particularly sphere of interest.

In these cases, we are simply growing pollution-tolerant animals within polluted microenvironments. Shortly I will be directly testing the toxicity of some salts and tank waters with larval bioassays, and I expect to show that there is a significant effect of such salts.

(note: I suspect that this water change regime does somewhat support your assertions).

Such a water change regime would be largely insignificant at reducing these materials. See my article in the April issue of [rk] for the effects of water changes.
 
rshimek said:
In these cases, we are simply growing pollution-tolerant animals within polluted microenvironments.

My pessimistic alter ego tells me that this will be helpful after mankind has destroyed the natural reefs with pollution and global warming. Perhaps one day aquarists will reintroduce their genetically modified corals back onto the dying reefs to replace the weak corals that couldn't handle the changes.

I suddenly feel like Dr. Moreau. Muahahahaha! :hmm6:
 
Levels of some trace elements, specifically nickel, copper, zinc and vanadium are well into the lethal range as it stands in our tanks, and we are losing or stressing animals because of this.

A pretty bold assertion for one who has never seen any toxicology data on reef tank systems.

"WE ARE LOSING" might better be written as "I have a hypothesis that the metals that I found in a test are within a toxic range if they were free metals. Of course, I do not know the bioavailability of any of these in a reef tank system, and have no evidence that they actually are toxic at these levels in systems with lots of chelating organics, but it is a situation worth exploring".
 
Originally posted by Randy Holmes-Farley

Hi Randy,

A pretty bold assertion for one who has never seen any toxicology data on reef tank systems.

I will be running some sea urchin bioassays on tank water and sea water mixes within the next month. Provided that I can complete the tests in time for MACNA, I will report on them there.

The statement is well supported. Bioassay data show that some corals, snails and other invertebrates die when exposed to the chemical concentrations found in our tanks. Our tanks are polluted with excess heavy metals far beyond what is reasonable.

Certainly just because such levels are toxic with animals tested in aquaria in a bioassay lab, of course doesn't mean they will be toxic in an aquarium in our house. There may be all sort of unproven, unfound, unknown, and truly magical factors that prevent the toxicity from occurring. Unfortunately, we have no evidence that such factors do occur or have any effects in home aquaria. Where the data that these mythical chelators exist and do as you suspect? - And suspect, with a complete absence of evidence, I might add.

We do know that concentrations of the chemicals seen our systems can cause toxic effects. We do know that they even if such metals are rendered temporarily insoluble that minor changes of condition can make them soluble and toxic.

And, if one looked at natural situations that were as polluted as our tanks are, they would be - and are - considered severely stressed. And like our tanks some animals grow in them, and even reproduce, but they a specialized subset, of pollution tolerant organisms.
 
I will be running some sea urchin bioassays on tank water and sea water mixes within the next month. Provided that I can complete the tests in time for MACNA, I will report on them there.

You'll of course need a control with everything (including organics) just the same, except the metals reduced to natural levels. How do you propose to do that? It seems unlikely to me that such a control is feasible since little is known about such organics, and without it, all you'll be able to do is say that reef tank water has a certain effect on sea urchin eggs, not that metals were responsible.

The statement is well supported. Bioassay data show that some corals, snails and other invertebrates die when exposed to the chemical concentrations found in our tanks.

Which corals? Any that people keep? If so, I take away just the opposite: they are alive at what your test suggests are high metal concentrations when data on pure systems says they should not be, so the situation is more complex that you are crediting it. Chelation of the metals seems a likely candidate for explaining the difference.

If they have not been kept alive in reef tanks, then I agree that the reason they have not MAY be metals, or it may be any of a number of other things that are different between our tanks and the ocean.

There may be all sort of unproven, unfound, unknown, and truly magical factors that prevent the toxicity from occurring. Unfortunately, we have no evidence that such factors do occur or have any effects in home aquaria. Where the data that these mythical chelators exist and do as you suspect? - And suspect, with a complete absence of evidence, I might add.

Ron, you are not the only scientist around. These are scientifically accepted facts for many stystems. In freshwater it is clear that copper is millions of times less toxic than in pure systems because of released chealtors. In marine systems, diatoms, algae and bacteria all release chelators the bind to many metals, such as iron. To suggest it is magircal because you are unaware of it is only natural, but not very scientific, or accurate.
 
Ron,

The statement is well supported. Bioassay data show that some corals, snails and other invertebrates die when exposed to the chemical concentrations found in our tanks. Our tanks are polluted with excess heavy metals far beyond what is reasonable.

Certainly just because such levels are toxic with animals tested in aquaria in a bioassay lab....


Toxicity of an element depends besides the concentration also very strongly on speciation.

So when you say that there are toxic concentrations in our tank are you just guessing or did you actually determine the speciation?

Where the data that these mythical chelators exist and do as you suspect? - And suspect, with a complete absence of evidence, I might add.

Mythical chelators do not exist. Natural chelators excreted by marine microorganisms, algae,....do exist.


clint:

That's great news and also bit surprising. I find it unbelievable that other "experts in the field" have never performed water quality test until know. Surely the companies that are selling these additives did similar tests to determine what elements to add to their product and in what quantities. Surely the people who have advocated regular dosing of these elements have some kind of chemical anaylsis to back their methods!?!?

We not only did the same type of tests but we went even much further.

I still advocate the use of some trace elements and will continue to do so. I can back this.
 
Thanks for entering the discussion, Habib.

I know that you posted a huge amount of data and links to papers on this topic in my forum a few minutes ago, and it would be great if you could bring it over here (a single cut and paste looses the links).

I'll bring over one that should dispell any idea that these effects are some type of magical illusion.

From the Marine Chemistry Group at the University of Plymouth (the bolding is mine):

"The uptake and availability of metal species to macrophytes (seaweeds) is currently under investigation within the group. Sensitive electrochemical techniques are used to determine the speciation of metals within culture media containing juvenile stages of seaweeds. These studies have shown that seaweeds release organic material which alters the metal speciation in the culture media. The concentration of this organic material (complexing ligand) released is dependant on both the growth of the the macrophyte and on the concentration of metal, perhaps indicating that these complexing ligands are released in a direct response to the presence of a toxic metal. . In parrallel to this, investigations are being undertaken into the intracellular production by algae of specific binding ligands (termed phytochelatins) in response to metals. The distribution and occurrence of phytochelatins is being investigated under laboratory conditions in order to assess the variation in response between different algal species and under variations in temperature and salinity. In addition, concentrations of phytochelatins in natural assemblages of phytoplankton in contaminated and uncontaminated estuaries are being measured. The aim of these studies is to relate phytochelatin production with metal toxicity and to develop a useful biomarker for metal contamination."

http://www.science.plymouth.ac.uk/D...chem.htm#Interactions between Trace metal and
 
Thanks for entering the discussion, Habib.

You are welcome!

I know that you posted a huge amount of data and links to papers on this topic in my forum a few minutes ago, and it would be great if you could bring it over here (a single cut and paste looses the links).

OK I will give it a try. If links are missing then I will try to correct it ASAP.

Here is one of my posts:

Tatu, Randy & others,

Sorry, it has become a tiny bit loooooooong:D

Toxicity of (trace) elements depends on the speciation, that is how it is present in the water column.

Free ionic forms will be far more toxic when present in high concentrations than organically bound forms.

The method used for measurement of the elements by Ron also measures besides the free ionic and organically bound forms also particulate forms. E.g. strongly adsorbed on other particles or as the solid oxide or carbonate forms. They will have no direct toxic effect.

Also the data in Ron's study regarding antimony and arsenic is IMO highly suspect. The values are high and are (virtually) the same for all tanks.


If it were known that reef tank inhabinants intentionally release species that control metal concentrations, and that these are not just random happenings but controlled events, then it brings validity that perhaps reef tank inhabitants, either intentionally or unintentionally, detoxify their own environment by releasing metal chelating agents.

O.K. here are some to start with.

The first one is easy to read and is very informative for a large crowd:

Chelation, uptake, and binding of trace metals

The following is the same as above but is the more scientific version:

Extra-cellular iron siderophores: structure and regulation

Another one:

Acquisition and Utilization of Transition Metal
In the above links you will find also other interesting pages on other topics.

The second parts deals with algae:
Intracellular binding: details


The following is from:

http://www.liv.ac.uk/~sn35/Documents/Research_Statement.html

Marine chemical findings
Our measurements are among the first to demonstrate that the biogenic metals (copper, zinc, iron, and cobalt) occur organically complexed in the oceans. Our measurements have shown that organic complexation reactions control the transport of copper, nickel and zinc through estuaries, and that dissolved metal concentrations in estuarine and coastal waters follow dynamic patterns. Unexpectedly anionic elements such as antimony, molybdenum, and uranium were also shown (by CSV) to occur to a significant extent as non-labile species in estuarine waters. A voltammetric study of the geochemistry of platinum in the Indian Ocean conclusively showed that this element has a geochemical behaviour reminiscent to that of manganese in those waters. Our investigations have shown that titanium and aluminium occur as unknown non-labile species, either colloidal or organically complexed, in the oceanic water column. We used our methods to determine the complex stability of sulfide with several metals in seawater, and found that the complex with copper is much more stable than expected.

Probably the most important finding of the last decade in oceanography has been that lack of iron limits oceanic productivity (the Iron Hypothesis). Our finding that iron is organically complexed provides the explanation for its apparent poor availability, and moderates the Iron Hypothesis to a combination of lack of iron and unavailability.

Photochemical effects and the existence of transient species were investigated in the field, showing that the redox chemistry of chromium appears to be controlled both by photochemical and biological processes in the upper water column, causing the presence of significant amounts of chromium(III) where it is thermodynamically unexpected.

We demonstrated that the biologically important folic acid and glutathione occur dissolved in the oceanic water column of the NE Atlantic. Further work has now shown the importance of thiols like glutathione on the chemical speciation of copper suggesting that thiols may well account for at least part of the ligands we see in natural waters.

The complexation reactions likely regulate the rate at which these metals are transferred through the membranes of microorganisms. For this reason we looked at interactions with microorganisms and found that marine algae (the important bloom forming coccolithophore Emiliania huxleyi) release iron-binding ligands in response to iron additions. This work stimulated the use of seawater cultures without modifier additions


Another one:

Nature 400, 858 - 861 (1999)



Competition among marine phytoplankton for different chelated iron species

DAVID A. HUTCHINS*, AMY E. WITTER*, ALISON BUTLERââ"šÂ¬Ã‚  & GEORGE W. LUTHER III*

* College of Marine Studies, University of Delaware, Lewes, Delaware 19958, USA
ââ"šÂ¬Ã‚  Department of Chemistry, University of California, Santa Barbara, California 93106, USA


Correspondence and requests for materials should be addressed to D.A.H. (e-mail: dahutch@udel.edu).




Dissolved-iron availability plays a critical role in controlling phytoplankton growth in the oceans,. The dissolved iron is overwhelmingly (99%) bound to organic ligands with a very high affinity for iron, but the origin, chemical identity and biological availability of this organically complexed Fe is largely unknown. The release into sea water of complexes that strongly chelate iron could result from the inducible iron-uptake systems of prokaryotes (siderophore complexes) or by processes such as zooplankton-mediated degradation and release of intracellular material (porphyrin complexes). Here we compare the uptake of siderophore- and porphyrin-complexed 55Fe by phytoplankton, using both cultured organisms and natural assemblages. Eukaryotic phytoplankton efficiently assimilate porphyrin-complexed iron, but this iron source is relatively unavailable to prokaryotic picoplankton (cyanobacteria). In contrast, iron bound to a variety of siderophores is relatively more available to cyanobacteria than to eukaryotes, suggesting that the two plankton groups exhibit fundamentally different iron-uptake strategies. Prokaryotes utilize iron complexed to either endogenous or exogenous siderophores, whereas eukaryotes may rely on a ferrireductase system, that preferentially accesses iron chelated by tetradentate porphyrins, rather than by hexadentate siderophores. Competition between prokaryotes and eukaryotes for organically-bound iron may therefore depend on the chemical nature of available iron complexes, with consequences for ecological niche separation, plankton community size-structure and carbon export in low-iron waters.


Citing a few:

Ahner, B. A.. Cornell University, baa7@cornell.edu
Oleson, J. A.. Cornell University, jro5@cornell.edu
Slinski, K. M.. Cornell University, kms32@cornell.edu


GLUTATHIONE CONCENTRATIONS IN FRESHWATER AND MARINE PHYTOPLANKTON

Small organic sulfur compounds play a large role in the intracellular speciation of trace metals in marine and freshwater algae. Glutathione, the principle free thiol in most algae, can complex metals directly or is polymerized enzymatically into metal-binding ligands called phytochelatins. In Emiliana huxleyi, concentrations of g-glutamyl cysteine (a precursor of glutathione) are significantly higher than glutathione which has implications with respect to phytochelatin synthesis. We have examined the effect of prolonged metal exposure on glutathione synthesis in both freshwater and marine algae. We found that deviation from control concentrations of glutathione is highly variable among species, though short-term exposure to Cd stimulates glutathione synthesis in some organisms. Utilizing published and experimentally determined binding constants for glutathione and phytochelatin it is possible to evaluate the probable intracellular speciation of various trace metals such as Cd and Hg. In addition, we are evaluating the use of various metal-specific fluorescent probes to quantify intracellular metal speciation.

From:

http://www.science.plymouth.ac.uk/DEPARTMENTS/Environmental/marchem/marine_chem.htm#Interactions%20between%20Trace%20metal%20and

The uptake and availability of metal species to macrophytes (seaweeds) is currently under investigation within the group. Sensitive electrochemical techniques are used to determine the speciation of metals within culture media containing juvenile stages of seaweeds. These studies have shown that seaweeds release organic material which alters the metal speciation in the culture media. The concentration of this organic material (complexing ligand) released is dependant on both the growth of the the macrophyte and on the concentration of metal, perhaps indicating that these complexing ligands are released in a direct response to the presence of a toxic metal. In parrallel to this, investigations are being undertaken into the intracellular production by algae of specific binding ligands (termed phytochelatins) in response to metals. The distribution and occurrence of phytochelatins is being investigated under laboratory conditions in order to assess the variation in response between different algal species and under variations in temperature and salinity. In addition, concentrations of phytochelatins in natural assemblages of phytoplankton in contaminated and uncontaminated estuaries are being measured. The aim of these studies is to relate phytochelatin production with metal toxicity and to develop a useful biomarker for metal contamination.

Other links:

Lack of phlorotannin induction in the brown seaweed Ascophyllum nodosum in response to increased copper concentrations

Bioavailability of biologically sequestered cadmium and the implications of metal detoxification

From the following link:


ABILITY OF IMMOBILIZED CYANOBACTERIA TO REMOVE

Reports also indicate that carboxyl groups on algal cell biomass are
responsible for binding to various ions (Gardea-Torresdey et al.,1990). Live algae possess
intracellular polyphosphates which participate in metal sequestration, as well as algal extracellular
polysaccharides that serve to chelate or bind metal ions (Zhang and Majidi,1994; Kaplan et
al.,1987; Van Eykelenburg,1978). Strains of Synechocystis spp. have been shown to develop a
thickened calyx when exposed to copper-stressed growth conditions (Gardea-Torresdey et
al.,1996a). Synechococcus sp. PCC 7942 was found to possess a copper-transporting P-type
ATPase in the thylakoid membrane (Bonilla et al.,1995). Synechococcus cedrorum 1191 was
shown to be tolerant to heavy metals and pesticides (Gothalwal and Bisen,1993). Other
investigators have studied the biosorption of heavy metals by algal biomass (Volesky and Holan,
1994; Volesky and Holan, 1995; Volesky and Schiewer, 1997). Such findings show the
possibility of manipulating or overexpressing existing resistance mechanisms and the use of such
organisms to remove harmful metals from the environment.



Other links:

The effect of Fe and Cu on growth and domoic acid production by Pseudo-nitzschia

See page #2 of:

Phytoplankton Physiology and Ecology of Metals
 
Originally posted by Randy Holmes-Farley

Hi Randy,

You'll of course need a control

Gee, will I really? Sage advice coming from some one, who has to the best of his published aquarium record, never run an experiment, or done a test.

I think you need to show that any organics are having any effect.

Until you do that you are simply "blowing smoke."

So, boy, spend some time and spend some money doing the work.

I would be glad to see a way of detoxifying these metallic poisons, and I would be more than happy to see you demonstrate it. But, you haven't done it....

Which corals? Any that people keep?

Try reading the article.

If so, I take away just the opposite

ROFL - It is truly fun to argue when you have absolutely no data to work from isn't it.

Do some experiments, collect some data. Then your arguments will have some credibility.

To suggest it is magircal because you are unaware of it is only natural, but not very scientific, or accurate.

To say that it is happening in a system when you have not ONE shred of evidence to support it, is absurd.
 
Originally posted by Habib

Habib,

Toxicity of an element depends besides the concentration also very strongly on speciation.

So when you say that there are toxic concentrations in our tank are you just guessing or did you actually determine the speciation?


These tests were run exactly as standard pollution monitoring tests are run. The data are compared in exactly the same manner with the same conclusions being reached.

If the tests show that levels of a certain metal kill animals, and if the tests show that the levels are above those levels, and animals do die then it is reasonable to suggest that the metal is responsible. It really doesn't matter the type of ion that is involved.

Mythical chelators do not exist. Natural chelators excreted by marine microorganisms, algae,....do exist.

I will grant you that they do. But there are no data that they are found in any concentrations in our aquaria, nor that they have any effect there.

We not only did the same type of tests but we went even much further.

Sure you did. Yup. Somewher you have those data....

Now lets see them published somewhere.

I can back this.

Publish the data.

It is really easy to criticize someone else without a stitch of published data to support your arguments.
 
Hi all,

No that I have stopped laughing, I had to chime in....

Dr. Ron,


More than likely, you - and most of us - have morphologies or species of corals that are pollution tolerant growing in our systems; in effect, they would have to be to survive. Such corals are found in nature, as well - but are not normally dominant as they generally grow slower and compete less well than their non-tolerant cousins. These animals likely be able to detoxify additional amounts of the toxic chemicals.


How lucky we are that the collectors target such pollution tolerant variants for the coral trade! How is that more rational than chelation as an explanation?

Did you poll the participants in your study to gather some meaningful guage of the health and survival of the animals in their aquariums?

Such data would be very telling in terms of the real toxicity of these agents in our tanks.

To say that it is happening in a system when you have not ONE shred of evidence to support it, is absurd

I think the posted abstracts represent far more than mere shreds!

Lastly, I hope that your response to the need for a control was only professional insult over the reminder, and not denial that it is necessary.

Please understand, I am not asserting that one hypothesis is more correct than the other. I believe that our corals probably to build tolerance, and I do believe that heavy metals are chelated. I mostly want to make the point that both hypotheseses must be tested (with controls!)

In a thread in Randy's forum, someone mentioned testing for heavy metals in skimmate. Elevated concentrations would be pretty compelling evidence for Randys theory.

Adam
;) ;)
 
Originally posted by Randy Holmes-Farley


From the Marine Chemistry Group at the University of Plymouth (the bolding is mine):

"The uptake and availability of metal species to macrophytes (seaweeds) is currently under investigation within the group.


Gee, I am so glad.

Sensitive electrochemical techniques are used to determine the speciation of metals within culture media containing juvenile stages of seaweeds. These studies have shown that seaweeds release organic material which alters the metal speciation in the culture media. The concentration of this organic material (complexing ligand) released is dependant on both the growth of the the macrophyte and on the concentration of metal, perhaps indicating that these complexing ligands are released in a direct response to the presence of a toxic metal.

Very nice, what algae or maybe what other plants... sea weeds, don' t they know which ones? More to the point does this happen with algae that occur in aquaria?

. In parrallel to this, investigations are being undertaken into the intracellular production by algae of specific binding ligands (termed phytochelatins) in response to metals. The distribution and occurrence of phytochelatins is being investigated

Lots of things are being investigated. To show that it works in a lab is nice. Now does it work anywhere else.

The aim of these studies is to relate phytochelatin production with metal toxicity and to develop a useful biomarker for metal contamination."

Hey, great, they will have a biomarker. So we can test our tanks and find that biomarker and know "fur shure" that metals toxicitiy is indeed occurring. LOL!

Basically what they are saying is that the metals are being toxic and they are finding a way in which some algae try to detoxify them. Well, I hope they find their marker, and I hope they can convince somebody to market the commercial version. It might be useful.

And what happens when the concentration rises yet futher?

This is nice post but it is simply irrelevent to our systems.
 
Originally posted by Habib

Also the data in Ron's study regarding antimony and arsenic is IMO highly suspect. The values are high and are (virtually) the same for all tanks.

Well, let's see... Arsenic was found only in one tank. Antimony in many. So, run tests on 20 random aquaria and see what you found.

You guys are missing the point....
  • The tests are the same ones that are used to detect high metals concentrations in environmental monitoring.
  • These tests are used to assess environmental conditions around polluted localities.
  • They work.
  • Positive high values are correlated with signficiant environmental degradation.
  • Such degradation has also been shown with corals under the same conditions.
  • Aquarists have problems keeping corals alive for extended periods, many other corals die immediately after they are added to tanks.
  • Every environmental scientist EVERY SINGLE ONE who works with these animals and who considers metals considers these materials as poisons.

We have concentrations of these materials, specifically Copper, Zinc, Nickel, and Vanadium from 10 to 500 x more concentrated in our tanks that in nature.

I suspect is it very reasonable to suggest these poisons are having an effect.

If they are not having an effect then it is incumbent upon Habib and Randy to demonstrate that they are not.

Sure there are data that in very low concentrations in natural environments, the metals may be - operative words - may be detoxified. So... show that it works in aquaria.

Get your hands wet, boys.....
 
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