Inland Reef / Reefs.org Salt Analysis Project

[Anonymous]

If you absolutely feel the need to test NSW again, may I suggest you collect one sample and have it tested BEFORE you spend money on anything else. You then can compare your results to Pilson to get a variance range...if there is too great of a variance you might want to rethink this a bit.

I seem to recall that recently there was some debate about Pilson or a similar reference because it was somewhat dated i.e. late 60's? Not that things have changed all that much but possibly the technology used to make those measurements could have been better? I may be mistaken or misinformed on that - my brain is a bit fried today - but I'll look into that further.

 

[saltshop]

Nope 1998.

Pilson, M. E. Q. 1998. An Introduction to the Chemistry of the Sea. Prentice-Hall, Inc. Upper Saddle River, NJ. 431 pp

 

[jamesw]

I think we should be able to obtain a water sample from Viti Levu Fiji for testing. I will work on getting one for testing.

Cheers
James

 

[randy holmes-farley]

Before doing any analytical tests of any salt mixes, I'd like to know whether there are any "toxicity" differences between them and natural seawater AFTER the water has been in a tank.

If tanks using NSW are no different than those using any random brand of ASW, then why spend all of the time and money to analyze the mixes?

The differences between the salt mixes could have been due to many different things: ammonia, nitrite, pH, aeration, organics added intentionally or as impurities, elevated or depleted inorganics other than the metals that Ron focussed on, the fact that some water samples were frozen and others not, etc.

Even if metals are responsible, it appears that tanks using NSW get equally high metals levels in short order in reef aquaria, so why obsess so strongly on the starting salt mix? Rather, folks should be looking at ways to keep metals out of tanks, and lower them in existing tanks. I've put all of this inbfo into an article for reefkeeping that will hopefully post in a month or two.

So that said, what I'd like to see is a stepped approach:

1. Test the toxicity of water drawn from tanks using NSW and ASW that are in other ways mostly equivalent.

2A. If there are big differences in toxicity, then look analytically to see what the real differences are (metals, etc).

2B. If there are not differences, then look at all of them relative to NSW to see why they might be more "toxic".

 

[Len]

Randy,

Out of curiosity, can you please qualify the following:
"Test the toxicity of water drawn from tanks using NSW and ASW that are in other ways mostly equivalent."

 

[aliendomain]

First I must say that I'm all for testing as many salts as possible for composition in an unbiased lab. But has anyone thought of looking for the composition of NSW from NOAA or one of the other national or international institutions?

 

[randy holmes-farley]

Out of curiosity, can you please qualify the following:
"Test the toxicity of water drawn from tanks using NSW and ASW that are in other ways mostly equivalent."

What I meant was to compare tanks with similar methods used to maintain them (same type of calcium and alkalinity supplementation and filtration, especially, since these things can impact metals delivery and export substantially). Compare these "equivalent" tanks when they use NSW and ASW.

 

[randy holmes-farley]

But has anyone thought of looking for the composition of NSW from NOAA or one of the other national or international institutions?

The composition of NSW is not the unknown. It is widely available. The question that may need verification is whether the tests used to show "elevated" metals in ASW will show lower levels in real NSW samples, and that the results on the ASW are not artifacts of the process somehow.

 

[aliendomain]

Randy,
I understand the mission is to determine what is in Synthetic Sea Salt Mixes vs. NSW, I think you missed my point. My question "But has anyone thought of looking for the composition of NSW from NOAA or one of the other national or international institutions?" was in respects to paying to have a lab test NSW vs. getting data that had already been collected.

 

[randy holmes-farley]

No, I understood that. But one should always make sure that the test (a nd collection methods, etc) that you are using to say that something is different than NSW is actually able to show that difference, and testing NSW is the best way to do that.

Suppose that all of the elevated metals come from improper use of ICP? After all, normal ICP (with atomic emission detection, not ICP-MS), as both Ron and Craig used, cannot detect the low levels of copper and other metals in NSW. So suppose that that test isn't appropriate. (I don't believe that because I've carefully (much more carefully than some reported studies) analyzed my tank for copper and get a similar value of 10-13 ppb, but I did not test NSW). Still it need to be accounted for.

Or that the storage containers are giving the signal, or who the heck knows what else. The negative control, of a seawater sample minus metals is critical to believing that salt mixes have elevated metals.

Then again, it's an altogether different question as to whether that relates to the observed toxicity.

 

[randy holmes-farley]

I also don't understand why we would want to test solid salt mixtures. We have all seen the loads of solids that don't dissolve, or at least precipitate after most of the salt dissolves. My container is coated white with it. Since that does not typically get into the tank, why would we want to test it? It might only make ASW look to have much higher metals than are really dissolved.

Since the test (ICP) uses liquids, that should be what we test (IMO). It is what I used in running ICP on my tank, and what Craig and Ron used, and what others have used on their samples. Are we really interested in pioneering new methodologies with the limited funds available, recognizing that we don't understand the complications?

Also, needing to test solids makes it very difficult to get a reasonable value for NSW. has anyone ever seen seawater tested in that fasghion? Not me, and there are presumably good reasons for that.

Personally, I also think there is a very good chance that ASW changes with time after mixing, with more and more insoluble things coming out of solution (including heavy metals). If true, that is a big complication to the entire study, but not one that suggests that testing solids would be more useful for undestanding tanks run with it.

 

[Eric Borneman]

Randy, John, and others. Great points.

First, I'd just like to say that despite any insufficiencies, statistical signficnaces, and methodological problems with Ron's work, the input of Randy, Habib and others have gone quite far into supplementing that work. This is some of the first real analysis of anecodte from the aquarium trade ever done, and I think it is very important - and, as Randy stated, of considerable concern. Everything Ron has found makes sense in my own observations in aquaria, and fits in well with what is known about the subject.

That said, I STRONGLY recommend that this project, of potentially immense significance, be approached carefully. I think many of the original suggestions, as previosly stated, might be interesting but may not be the way to approache this right now. Andrew, John, Randy and others have pointed out some of these issues.

Right now, I think that donations should be solicited, and that a valid protocol be drafted by those with scientific background. In other words, a hypothesis, methods, controls, etc. I also strongly suggest that Randy, Habib and Craig should ultimately lead this project if they have the time and inclination. Experimental design is not for amateurs, and this subject, despite the number of well meaning and interested backyard chemists in this hobby, will take considerable thought and effort.

In particular, the most recent work by Shimek (as pointed out) was a bioassay, not a metal composition test. Those analyses preceeded the current work. All in all, this series progressed logically. Observations led to testing of potential effectors in a tank concentrating on metals. Water samples showed high levels of metals. Food analysis showed high levels of metals. Salts showed high levels of metals. Testing using a bioassay showed some salt mixes to be larvotoxic.

Playing devil's advocate or just doubting the work is childish. Repeitition of the same study is science, but perhaps uneccesary. The fact that manufacturer's calims were used for analysis is relatively unimportnat to the validity of the study, although analysis would go a long way to confirming a significant correlation between composition and larvotoxicity. Personally, the assays seem more important and may be cheaper than complicated analysis of each salt. If the salts are ultimately toxic, I don;t want them no matter what they contain. They would just be "out". Then, of the ones that appear to be relatively safe, those could be used as subjects of the more intesive and expensive analysis.

Expanding the scope or bettering the materials and methods is science. Trying to tackle every issue and question in one felt swoop will probably introduce significant error, may be less than feasable, and is likely not economical. The use of the aforementioned chemists is almsot assuredly the way to proceed. The support of the hobby is desperatey needed and any donation will almost asusredly be made up in lives saved and potential gains in fecundity.

I am sending in my donation, and hope that this study is fruitful.

 

[jamesw]

Randy:

You wrote:

Before doing any analytical tests of any salt mixes, I'd like to know whether there are any "toxicity" differences between them and natural seawater AFTER the water has been in a tank.

Isn't this what you have been asking Dr. Shimek to do for almost 6 months now? Have you given up - and decided that maybe in organizing this study we will listen to your input where it has gone unheeded before?

If so - thanks for putting some thought into this. I can assure yourself and Eric that we are taking your input into consideration. We will support Inland Reef in their endeavor, and we may consider throwing some of the "heavyweights" in this hobby into this study (if they are willing to be "thrown" ) who are well respected and knowledgeable in this area. I think the study would benefit tremendously from some oversight by someone with a biochemistry background.

Sincerely,
James Wiseman

 

[Eric Borneman]

James:

Good intentions aside, the little preliminary plan devised on p. 1. isn't a "study." Its an excercise in curiosity that may or may not show much. This has to start with a hypothesis. What is it? How many replicates? n=1? That's a problem. What are the controls? Positive and negative? I see some general methods, but once you get some data, how will you analyze them? Depending on what you do, you could have some hugely complicated statistics. What statistics will you plan to use? These are all things that need to be addressed before you proceed and start soliciting for 10,000 bucks, plus. This is a lot of money, as you realize, and a budget would probably be a nice thing to offer while soliciting these donations. These are the reasons you guys should do more than "consider" soliciting help. You should absolutely require it.

 

[MattM]

Eric & Randy -

Welcome! We've been waiting for you to chime in on this.

If you notice, the plan I posted is marked as "preliminary." Nothing is in concrete and we certainly welcome the assistance of you "pros" to make this effort more worthwhile.

Maybe the interested parties could get together via e-mail, teleconference, or a private forum to hash out where we should go. I'm thinking James would be the person to organize this.

Thoughts?

 

[liquid]

I'm thinking James would be the person to organize this.

Thoughts?

I would concur since this started out here. I'm sure we'll hear from James shortly on this.

Shane

 

[JohnL]

I think Eric and Randy would be much better choices to lead this effort.

I'm thinking James would be the person to organize this.

Thoughts?

I would concur since this started out here. I'm sure we'll hear from James shortly on this.

Shane

btw, Shane, this started with an article in this month's Reefkeeping magazine

 

[JohnL]

Isn't this what you have been asking Dr. Shimek to do for almost 6 months now? Have you given up - and decided that maybe in organizing this study we will listen to your input where it has gone unheeded before?

That's really un-called for, James. :roll:

 

[randy holmes-farley]

Organization aside, one other set of comments about testing NSW:

1. For a long time, scientists thought that NSW had much higher levels of metals than they do now. Not a small difference, but orders of magnitude. This is clear in Ron's first article where he posted some NSW values, but then corrected them in later articles when newer data was provided. Why is that? Because collecting samples of NSW and not contaminating it with metals from the containers and such is VERY difficult.

For example, from Millero in "Chemical Oceanography" (1996):

"In recent years there has been a rapid increase in our knowledge of the distribution of minor trace elements (mostly metals) in the oceans. THis recent revolution is related to major advances in instrumentation and elimination or control of contamination during sampling, storage, and analysis"

IMO, the use if ICP-MS will fit the instrument part, but the sampling, storage, and analysis part remains a concern to me. Millero goes on to describe teflon bottles and ultraclean room techniques for sample handling.

2. If you collect samples of NSW from any particular location near a coast, the sample may well already itself be contaminated with metals from sewage, agricultural runoff, etc. THis effect has been documented many times in the literature. Here's an example from last year, including some samples local to Matt:


Comparison of Copper Speciation in Coastal Marine Waters Measured Using Analytical Voltammetry and Diffusion Gradient in Thin-Film Techniques. Twiss, Michael R.; Moffett, James W. Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA, USA. Environmental Science and Technology (2002), 36(5), 1061-1068.

Abstract

The diffusion gradient in thin-film hydrogel (DGT) probe is a promising tool for metal speciation work. Based on a passive sampling principle, it provides the potential for large data sets in complex regimes. DGT probes were deployed in waters characterized independently using competitive ligand exchange-adsorptive cathodic stripping voltammetry (CLE-ACSV). The CLE-ACSV used benzoyl acetone as the competitive ligand in discrete water samples collected during the deployment of the DGT probes. The DGT probes used a 15% polyacrylamide/0.4% bisacrylamide cross-linker hydrogel and a Na form of Chelex-100 to complex metal that fluxed into the probe through the hydrogel. Probes were deployed in locations characterized by the degree of pollution impact: the relatively pristine Vineyard Sound, Massachusetts, [Cu]total »6nM; small seasonally active harbors on Cape Cod, Massachusetts, [Cu]total = 12-64nM; as well as a large polluted estuary, the Elizabeth River, Virginia, [Cu]total = 44-58nM; and a large polluted port, San Diego Harbor, California, [Cu]total = 23-103nM. This is the first study where DGT probes have been compared with an independent speciation technique in marine systems and used to establish the diffusion coeff. of Cu-complexing ligands in situ. The results showed that the probes produced highly precise data sets, with substantial differences in copper accumulation between contaminated and pristine waters. Comparison of DGT results with CLE-CSV indicate that at least 10-35% of the organically complexed copper derived by CLE-ACSV measurements was DGT-labile. Diffusion coeffs. (cor. to 25°) of organically complexed DGT-labile Cu through the hydrogel ranged from 0.77 ´ 10-6 cm2/s in Vineyard Sound to 2.16 ´ 10-6 cm2/s in the Elizabeth River estuary. Accumulation rates of copper were substantially higher in contaminated waters than in pristine waters, suggesting that the probes in their current form may be useful as tracking tools to detect episodic sources of contamination.

 

[Eric Borneman]

I agree John...I was shocked myself.

That aside, and thanks for thumbs up from some of you, but I am not the person for this job. Those listed are. Ron knows far more about urchins and the bioassays, the others know far more about chemistry. If you guys need my help in background research of the topic, biology input, review of the design, etc., I'd love to help. But, I lack the expertise in this subject that the others have.

I just think projects like this are imperative in furthering the hobby, and would hate to see their value lost by the same psuedo-science that has caused many of the problems that exist in the first place. This is step one towards a better hobby and less anecdote.

I would much rather put the time, effort and money into something like this than another "blind" trial of "let's see if doing ____ this time will help this thing alive" or " I have kept one for six months and I do this" and hope others feel and will do the same. The money spent is money saved in the long run..tangibly...and the effort spent might even save time from answering and posting conjecture as to why things have gone wrong in so many cases.

This is literally a sort of pilot project, spawned by the abiities and desires of Ron to provide real information to this hobby. I think it would be disrespectful and foolish to not involve the man with the experience in this area, and I might add, one of only a handful of real marine scientists in this hobby. This will hopefully be the first of a string of real studies that could literally start at any aspect of the hobby and get rid of the myths. Lighting data, such as those provided by Sanjay, and a smattering of other aquarium studies generally distinctly lacking in scope or method, are among the only things that have been somewhat addressed. There are hundreds of questions, but I would say that those directly acting on the shortcomings of closed systems are among the most important. And toxic things have great effects in small water volumes.

I do have a very good biostatistician in my department that I would be happy to ask his input if needed. You all have know you have access to my considerable literature resources and I'd be happy to provide them and any further material to those that ultimatley need them for this project. I'd say that a review of methodologies previously employed in this type work would be a good starting point, although I'm sure Randy, Habib, Ron and others are well aware of them, too. I'd also say that anyone invovled in planning this project acquire and familiarize themselves with background material thoroughly before jumping headfirst into this and making decisions and suggestions about how to proceed.