Thanks so much Ralph!
:beer:
What you need to know about copper and coral
- Thread starter IridescentLily
- Start date
:beer:
If the manufacturer of the Polyfilter adds copper to prevent it from reducing copper below say 30 ppb and if the tank water is below this level, then the copper in the Polyfilter will go into the tank water, increasing the copper level until the copper in the Polyfilter is exhausted or reaches the 30 ppb level.
Under the data they previously published, the polyfilter will release copper to a 0.01 ppb copper tank. Whether it ever rises to 30 ppb in the tank depends on how much polyfilter is used in how much tank water, but yes, adding enough polyfilter could raise it as high as 30 ppb. Adding more beyond that should not raise it further.
If a tanks starts higher than 30 ppb, then using a polyfilter will bring it down to 30 ppb, if enough is used, and if not, then it will bring it toward 30 ppb.
That analysis all is based on inorganic copper. Since organic binding to copper will be fairly extensive, and since there are tons of different organics and each form will bind (or not) differently to a polyfilter, one cannot really say much about that, except I would not assume that binding or organic forms is better to a polyfilter than to other organics binders such as GAC.
Is the copper in the polyfilter chelated or in the ionic form?
I expect it is inorganic copper chelated by the polyfilter itself.
There will be some exchange of inorganic and organic bound copper, but how fast and how extensively depends on the organic itself.
Under the data they previously published, the polyfilter will release copper to a 0.01 ppb copper tank. Whether it ever rises to 30 ppb in the tank depends on how much polyfilter is used in how much tank water, but yes, adding enough polyfilter could raise it as high as 30 ppb. Adding more beyond that should not raise it further.
If a tanks starts higher than 30 ppb, then using a polyfilter will bring it down to 30 ppb, if enough is used, and if not, then it will bring it toward 30 ppb.
That analysis all is based on inorganic copper. Since organic binding to copper will be fairly extensive, and since there are tons of different organics and each form will bind (or not) differently to a polyfilter, one cannot really say much about that, except I would not assume that binding or organic forms is better to a polyfilter than to other organics binders such as GAC.
Is the copper in the polyfilter chelated or in the ionic form?
I expect it is inorganic copper chelated by the polyfilter itself.
There will be some exchange of inorganic and organic bound copper, but how fast and how extensively depends on the organic itself.
HighlandReefer
Team RC
Thanks Randy for the explanation.
From your explanation, perhaps running a polyfilter all the time is not the best way to go since it may increase already lower levels of copper. Perhaps a polyfilter should only be used if one suspects a high level of ionic copper in excess of 30-40 ppb.
Perhaps as a maintenance procedure to help reduce copper (and other heavy metals), running Cuprisorb would be more appropriate?
From your explanation, perhaps running a polyfilter all the time is not the best way to go since it may increase already lower levels of copper. Perhaps a polyfilter should only be used if one suspects a high level of ionic copper in excess of 30-40 ppb.
Perhaps as a maintenance procedure to help reduce copper (and other heavy metals), running Cuprisorb would be more appropriate?
If they still, in fact, add copper, I would not run a polyfilter unless there was a substantial concern over copper. Yes, cuprisorb may be better in that application.
HighlandReefer
Team RC
I decided to send an email to Poly-Bio-Marine, Inc. to see if they had any information to add to this article and this is their response:
In a message dated 12/18/2011 10:20:49 A.M. Eastern Standard Time, Cliff Babcock writes:
I have written an article in this month's Reef Keeping Magazine regarding copper and its effect on coral.
The subject has come up questioning the formulation used in the Polyfilter and that copper is added to it to maintain a level of around 30 ppb.
Is there anything you would like me to add to this thread?
Cliff,
---------------------------------------------------------------------------------------
We don't directly add trace elements into Poly-Filter (R) instead the trace elements 'are
actually adsorbed into Poly-Filter's molecular Terpolymer structure . After manufacturing
Poly-Filters are placed into chemically inert process tanks (filled with synthetic saltwater)
and the saltwater is pumped over the filters for two days. The salt water is changed
twice during this two day adsorption process. During this time Poly-Filter (R) adsorbs the
trace metals out the synthetic saltwater. After process completion the Poly-Filter (R) are
rinsed in sterile, highly filtered freshwater then dried for packaging. The salt used for this
process is Marine Enterprises Crystal Sea Bio Assay formula. The water used to
hydrate the Crystal Sea Bio Assay salt is sterile , highly filtered well water.
The trace elements adsorbed into Poly-Filter (R) are bound sufficiently that the only
way to extract them is through immersion in a 5.0 % strong mineral acid (Hydrochloric,
Sulfuric or Nitric acid ) solution. Leach out of the adsorbed trace elements is impossible
in freshwater , brackish or saltwater .
During our Poly-Filter (R) copper testing ( UMDNJ Toxicology Dept ) using Graphite furnace ,
Atomic Absorption (US EPA Standards) we found marine salts contained between 30.0 -
40.0 micrograms per liter Copper. We hydrated marine salts with high filtered freshwater
and 0.056 micro Siemens/cm 2 sterile, medical grade ultra pure water. We doubt that any
marine salt or reef salt mixture , hydrated using R/O + D. I. , would contain a copper concentration
below 20 ng/ml or 20 microgram per liter . Again this statement is based upon the testing
laboratory having had a factory technician calibrate the Atomic Absorption (Graphite furnace )
using standards prepared under US FDA protocols. Other studies that reported
synthetic saltwater copper concentrations of 20 ng/ml or 20 micrograms per liters didn't use
a factory calibrated , Atomic Absorption with Graphite furnace having standards prepared using
US FDA protocols. Instead they used Atomic Absorption without Graphite furnace or ICP using
lab standards which does not have the accuracy of our 1997 UMDNJ Toxicology Dept study .
Ken Howery, President
Poly-Bio-Marine, Inc.
O.E. Manufacturer
Filtration Systems
Est. 1976
In a message dated 12/18/2011 10:20:49 A.M. Eastern Standard Time, Cliff Babcock writes:
I have written an article in this month's Reef Keeping Magazine regarding copper and its effect on coral.
The subject has come up questioning the formulation used in the Polyfilter and that copper is added to it to maintain a level of around 30 ppb.
Is there anything you would like me to add to this thread?
Cliff,
---------------------------------------------------------------------------------------
We don't directly add trace elements into Poly-Filter (R) instead the trace elements 'are
actually adsorbed into Poly-Filter's molecular Terpolymer structure . After manufacturing
Poly-Filters are placed into chemically inert process tanks (filled with synthetic saltwater)
and the saltwater is pumped over the filters for two days. The salt water is changed
twice during this two day adsorption process. During this time Poly-Filter (R) adsorbs the
trace metals out the synthetic saltwater. After process completion the Poly-Filter (R) are
rinsed in sterile, highly filtered freshwater then dried for packaging. The salt used for this
process is Marine Enterprises Crystal Sea Bio Assay formula. The water used to
hydrate the Crystal Sea Bio Assay salt is sterile , highly filtered well water.
The trace elements adsorbed into Poly-Filter (R) are bound sufficiently that the only
way to extract them is through immersion in a 5.0 % strong mineral acid (Hydrochloric,
Sulfuric or Nitric acid ) solution. Leach out of the adsorbed trace elements is impossible
in freshwater , brackish or saltwater .
During our Poly-Filter (R) copper testing ( UMDNJ Toxicology Dept ) using Graphite furnace ,
Atomic Absorption (US EPA Standards) we found marine salts contained between 30.0 -
40.0 micrograms per liter Copper. We hydrated marine salts with high filtered freshwater
and 0.056 micro Siemens/cm 2 sterile, medical grade ultra pure water. We doubt that any
marine salt or reef salt mixture , hydrated using R/O + D. I. , would contain a copper concentration
below 20 ng/ml or 20 microgram per liter . Again this statement is based upon the testing
laboratory having had a factory technician calibrate the Atomic Absorption (Graphite furnace )
using standards prepared under US FDA protocols. Other studies that reported
synthetic saltwater copper concentrations of 20 ng/ml or 20 micrograms per liters didn't use
a factory calibrated , Atomic Absorption with Graphite furnace having standards prepared using
US FDA protocols. Instead they used Atomic Absorption without Graphite furnace or ICP using
lab standards which does not have the accuracy of our 1997 UMDNJ Toxicology Dept study .
Ken Howery, President
Poly-Bio-Marine, Inc.
O.E. Manufacturer
Filtration Systems
Est. 1976
Thanks.
Some of that is wrong, like the parts on salt mixes having high copper and how that was tested, but they clearly do add copper and such into the Poly Filter still.
Whether it comes out or not in reef tank water with low copper is perhaps an open question, but if it does not then their whole rational for equilibrating raw polyfilters with artificial seawater prior to use doesn't make sense to me. If it is not an equilibrium process, then simply occupying some of the sites with trace metals won't impact its ability to further bind more metals into still available sites to levels below that present in the equilibrating seawater, which is the stated reason for doing it.
Note that they do not address that organics in reef tank water might be as good or better chelators than their media and may strip it away. That's a very different scenario than pure fresh water or artificial seawater.
Some of that is wrong, like the parts on salt mixes having high copper and how that was tested, but they clearly do add copper and such into the Poly Filter still.
Whether it comes out or not in reef tank water with low copper is perhaps an open question, but if it does not then their whole rational for equilibrating raw polyfilters with artificial seawater prior to use doesn't make sense to me. If it is not an equilibrium process, then simply occupying some of the sites with trace metals won't impact its ability to further bind more metals into still available sites to levels below that present in the equilibrating seawater, which is the stated reason for doing it.
Note that they do not address that organics in reef tank water might be as good or better chelators than their media and may strip it away. That's a very different scenario than pure fresh water or artificial seawater.
HighlandReefer
Team RC
Thanks Randy.
I have sent another email for any response to your concerns. I have encouraged Poly-Bio-Marine, Inc. to post directly here in this thread if they like.
I too am interested in any response they may have regarding the questions you have posed.
I have sent another email for any response to your concerns. I have encouraged Poly-Bio-Marine, Inc. to post directly here in this thread if they like.
I too am interested in any response they may have regarding the questions you have posed.
:thumbsup:
Well see.
Well see.
FWIW, there appears to be another good way to possibly and routinely remove copper from reef aquaria, but I cannot say anything until the experiment that I reviewed today for someone else is published.
disc1
-RT * ln(k)
FWIW, there appears to be another good way to possibly and routinely remove copper from reef aquaria, but I cannot say anything until the experiment that I reviewed today for someone else is published.
Tease...
HighlandReefer
Team RC
:lol:
Patience....
So just to make sure folks understand my position on some of these products...
First, any copper detectable with a test kit is likely too much. For a healthy reef tank, you will not be able to monitor copper levels with a kit at low enough levels with sufficient reliability. In accidents (like a spill of fish med into the reef tank) or fish treatments (as in a hospital tank), however, you can often detect copper with a kit.
Cuprisorb and Polyfilters are booth seemingly a good way to deal with substantially elevated copper levels. I've recommended both hundreds of times. There are likely also other ways that work, but as of today, these are good choices for that application.
If you have what I consider "normal" reef aquarium levels of copper, and by that I mean maybe 5-30 ppb and you want to lower copper further, I would not use a Polyfilter because the manufacturer preloads them with copper (and other ions) sufficient that by their own claims, it won't reduce copper further. Whether it adds any to the aquarium in that context is debatable and, at present, unknown to me, but it is clear it should not remove any as that was the reason for the manufacturer to copper to Polyfilters in the first place.
Cuprisorb may be a similar (or identical) product for which they do not make any claims about preloading them with copper (that I have seen), and Cuprisorb may function for the purpose of lowering copper below 30 ppb, although I've not seen any data suggesting it will (or won't). If very low copper levels are a goal (say, 5 ppb), then Cuprisorb would probably be my recommendation at this point.
Exporting organic matter in a variety of ways, such as by skimming, will help export copper, and I think many of these methods can be useful. It is not clear, however, how effective that will be overall.
In my careful testing of my reef aquarium water a few years ago, I detected about 10-15 ppb copper in my tank using no special means for copper export aside from normal skimming (and, IIRC, using GAC). In an identical test of the Instant Ocean I used as a salt mix at the time, I detected none, which in this case means less than 10 ppb or so.
This article details a number of thoughts relating to trying to keep an aquarium with low metals:
Reef Aquaria with Low Soluble Metals
http://reefkeeping.com/issues/2003-04/rhf/feature/index.php
First, any copper detectable with a test kit is likely too much. For a healthy reef tank, you will not be able to monitor copper levels with a kit at low enough levels with sufficient reliability. In accidents (like a spill of fish med into the reef tank) or fish treatments (as in a hospital tank), however, you can often detect copper with a kit.
Cuprisorb and Polyfilters are booth seemingly a good way to deal with substantially elevated copper levels. I've recommended both hundreds of times. There are likely also other ways that work, but as of today, these are good choices for that application.
If you have what I consider "normal" reef aquarium levels of copper, and by that I mean maybe 5-30 ppb and you want to lower copper further, I would not use a Polyfilter because the manufacturer preloads them with copper (and other ions) sufficient that by their own claims, it won't reduce copper further. Whether it adds any to the aquarium in that context is debatable and, at present, unknown to me, but it is clear it should not remove any as that was the reason for the manufacturer to copper to Polyfilters in the first place.
Cuprisorb may be a similar (or identical) product for which they do not make any claims about preloading them with copper (that I have seen), and Cuprisorb may function for the purpose of lowering copper below 30 ppb, although I've not seen any data suggesting it will (or won't). If very low copper levels are a goal (say, 5 ppb), then Cuprisorb would probably be my recommendation at this point.
Exporting organic matter in a variety of ways, such as by skimming, will help export copper, and I think many of these methods can be useful. It is not clear, however, how effective that will be overall.
In my careful testing of my reef aquarium water a few years ago, I detected about 10-15 ppb copper in my tank using no special means for copper export aside from normal skimming (and, IIRC, using GAC). In an identical test of the Instant Ocean I used as a salt mix at the time, I detected none, which in this case means less than 10 ppb or so.
This article details a number of thoughts relating to trying to keep an aquarium with low metals:
Reef Aquaria with Low Soluble Metals
http://reefkeeping.com/issues/2003-04/rhf/feature/index.php
HighlandReefer
Team RC
Thanks for the summary Randy. It is difficult when all the necessary information is not disclosed by manufacturers to help make the best decision as to which products would be useful to hobbyists and in which scenarios.
I would like to point out that very few manufacturers have cooperated with us like Habib (owner of Salifert) has in the past. I assume some of Salifert's success may be credited to this. After all a little sugar goes a long way.
I would like to point out that very few manufacturers have cooperated with us like Habib (owner of Salifert) has in the past. I assume some of Salifert's success may be credited to this. After all a little sugar goes a long way.
I used an ICP-OES in the same way that I tested some supplements in this article:
Purity of Calcium Chloride
http://www.advancedaquarist.com/issues/mar2004/chem.htm
Such testing needs to be done carefully. I've sometimes been concerned with studies by folks who do such work who just send samples out for lab analysis (even "official" methods), and do not even double check to see whether the answers they get are within the limits of accurate quantitation of the device, or if none is detected, what that means, and in some cases, the answer might even just be integration of noise or interference due to other ions.
Here's a discussion of what I did:
ICP Testing Methods
There has recently been a significant amount of discussion in the hobby concerning analytical methods. Richard Harker has recently authored two articles that demonstrate some concerns with a particular method involving ICP (Inductively Coupled Plasma; Article 1, Article 2). In this technique, the liquid sample is injected into an incredibly hot plasma, completely breaking the sample down into individual elemental ions. There are a variety of ways to then detect these ions, including mass spectroscopy (called ICP-MS) and from the intensity of different wavelengths of light emitted from the different ions (called ICP-OES, with OES standing for Optical Emission Spectroscopy).
I have chosen to use ICP-OES, largely because it is the instrument that I have available (A Varian Vista-MPX). It is also the method that Richard Harker has claimed to be problematic when using a particular protocol (ICP Scan, EPA method 200.7). I share some of his concerns about the use of ICP, particularly for ions that are near their detection limits. In fact, I believe that some analyses reported in the aquarium literature using ICP-OES may simply reflect instrumental and sample noise that was added up by the software used with the instrument to report an artificially high value. I have discussed this concern in the past, for example, for aluminum.
In all ICP-OES data that I have presented in prior articles, as well as all data in this article, such issues are not a consideration for the reader. I have carefully looked at the emission data for each ion and for each sample, with my own eyes, to confirm whether the data claimed by the software is a real emission, or just noise. For all signals near the noise level, I spiked small but known amounts of commercial ICP standards into these calcium chloride solutions to see exactly how high of a concentration would have to be present in these solutions to be able to see real signals. These detection limits are often different than the detection limits stated by the instrument manufacturer (since those stated values do not take into account the nature of other interfering ions in your test sample, such as a huge background of calcium and chloride), and are shown later in the article. I have also tested the highly purified water used to dissolve the solid samples in this study. This type of protocol takes much more effort than running the sort of ICP scan that Harker has discussed. Nevertheless, it is important when trying to understand the limits of the data obtained.
This process is shown in Figure 1. Figure 1 is a plot of the emission intensity in one of the wavelength regions expected to have emissions from cadmium. The bottom spectrum in Figure 1 is part of the emission from the Dow sample. There is no apparent peak at 228.802 nm where one expects one of the emission peaks for cadmium. However, when 0.1 ppm cadmium is added to this sample (top spectrum in Figure 1), the cadmium emission is clearly seen. Adding 0.02 ppm Cd instead of 0.1 ppm results in a smaller, but still clearly defined peak above the background noise. From those results, I conclude that the Dow sample has less than 0.02 ppm cadmium.
Figure 1. Emission spectrum in the region of one of the emissions from cadmium. The bottom curve represents the emission from the Dow sample. The upper curve represents this same sample spiked with 0.1 ppm cadmium. The H-shaped symbol in the middle represents the region actually integrated to collect data (between the vertical lines).
Figure 2 shows the cadmium emission from the Kent Turbo Calcium sample. Even without any extra cadmium added, it has a clearly defined cadmium peak at 228.802 nm. When that peak area is compared to cadmium standards, I conclude that it has about 0.07 ppm cadmium. This process was repeated for 2-3 emission peaks for each ion and for each sample. The tabulated results represent an average of these values for each ion. Table 1 shows the limits of detection that I determined using the above process for many of the ions tested in this article (for most of the other ions, the limit of detection was far below the values found).
Figure 2. Emission spectrum in the region of one of the emissions from cadmium for the Kent Turbo Calcium sample. The H-shaped symbol in the middle represents the region actually integrated to collect data (between the vertical lines).
In short, and summarized for folks that do not have much interest in instrumental methods:
Note: The data in this article do not suffer from any of the complications previously discussed by Harker and others relating to ICP, and can be considered reliable indications of what was present in the samples tested.
Purity of Calcium Chloride
http://www.advancedaquarist.com/issues/mar2004/chem.htm
Such testing needs to be done carefully. I've sometimes been concerned with studies by folks who do such work who just send samples out for lab analysis (even "official" methods), and do not even double check to see whether the answers they get are within the limits of accurate quantitation of the device, or if none is detected, what that means, and in some cases, the answer might even just be integration of noise or interference due to other ions.
Here's a discussion of what I did:
ICP Testing Methods
There has recently been a significant amount of discussion in the hobby concerning analytical methods. Richard Harker has recently authored two articles that demonstrate some concerns with a particular method involving ICP (Inductively Coupled Plasma; Article 1, Article 2). In this technique, the liquid sample is injected into an incredibly hot plasma, completely breaking the sample down into individual elemental ions. There are a variety of ways to then detect these ions, including mass spectroscopy (called ICP-MS) and from the intensity of different wavelengths of light emitted from the different ions (called ICP-OES, with OES standing for Optical Emission Spectroscopy).
I have chosen to use ICP-OES, largely because it is the instrument that I have available (A Varian Vista-MPX). It is also the method that Richard Harker has claimed to be problematic when using a particular protocol (ICP Scan, EPA method 200.7). I share some of his concerns about the use of ICP, particularly for ions that are near their detection limits. In fact, I believe that some analyses reported in the aquarium literature using ICP-OES may simply reflect instrumental and sample noise that was added up by the software used with the instrument to report an artificially high value. I have discussed this concern in the past, for example, for aluminum.
In all ICP-OES data that I have presented in prior articles, as well as all data in this article, such issues are not a consideration for the reader. I have carefully looked at the emission data for each ion and for each sample, with my own eyes, to confirm whether the data claimed by the software is a real emission, or just noise. For all signals near the noise level, I spiked small but known amounts of commercial ICP standards into these calcium chloride solutions to see exactly how high of a concentration would have to be present in these solutions to be able to see real signals. These detection limits are often different than the detection limits stated by the instrument manufacturer (since those stated values do not take into account the nature of other interfering ions in your test sample, such as a huge background of calcium and chloride), and are shown later in the article. I have also tested the highly purified water used to dissolve the solid samples in this study. This type of protocol takes much more effort than running the sort of ICP scan that Harker has discussed. Nevertheless, it is important when trying to understand the limits of the data obtained.
This process is shown in Figure 1. Figure 1 is a plot of the emission intensity in one of the wavelength regions expected to have emissions from cadmium. The bottom spectrum in Figure 1 is part of the emission from the Dow sample. There is no apparent peak at 228.802 nm where one expects one of the emission peaks for cadmium. However, when 0.1 ppm cadmium is added to this sample (top spectrum in Figure 1), the cadmium emission is clearly seen. Adding 0.02 ppm Cd instead of 0.1 ppm results in a smaller, but still clearly defined peak above the background noise. From those results, I conclude that the Dow sample has less than 0.02 ppm cadmium.
Figure 1. Emission spectrum in the region of one of the emissions from cadmium. The bottom curve represents the emission from the Dow sample. The upper curve represents this same sample spiked with 0.1 ppm cadmium. The H-shaped symbol in the middle represents the region actually integrated to collect data (between the vertical lines).
Figure 2 shows the cadmium emission from the Kent Turbo Calcium sample. Even without any extra cadmium added, it has a clearly defined cadmium peak at 228.802 nm. When that peak area is compared to cadmium standards, I conclude that it has about 0.07 ppm cadmium. This process was repeated for 2-3 emission peaks for each ion and for each sample. The tabulated results represent an average of these values for each ion. Table 1 shows the limits of detection that I determined using the above process for many of the ions tested in this article (for most of the other ions, the limit of detection was far below the values found).
Figure 2. Emission spectrum in the region of one of the emissions from cadmium for the Kent Turbo Calcium sample. The H-shaped symbol in the middle represents the region actually integrated to collect data (between the vertical lines).
In short, and summarized for folks that do not have much interest in instrumental methods:
Note: The data in this article do not suffer from any of the complications previously discussed by Harker and others relating to ICP, and can be considered reliable indications of what was present in the samples tested.
Last edited:
For more info on copper specifically, I showed the wavelengths I used for the the ICP-OES in a previous article on limewater self purification and presume I did the same on my tank water:
http://reefkeeping.com/issues/2003-05/rhf/feature/index.htm
I monitored copper concentrations using a modern analytical lab technique: Inductively Coupled Plasma (ICP) using atomic emission detection. I used two different emission peaks (324.754 and 327.395 nm).
The use of multiple wavelengths was how I got a slightly better limit of quantitation than the machine qoutes (it claims 20 ppb). I could easily see a 10 ppb peak, but could not see a true peak below that. For my tank I saw clear peaks a bit bigger than the 10 ppb standard but below the 20 ppb. There was no clear peak in Instant Ocean.
My low metals article I posted above has a statement about the amount I found in my tank (10-13 ppb).
http://reefkeeping.com/issues/2003-04/rhf/feature/index.php
but at this moment I cannot find the first place I reported the copper levels in my tank and the details of doing so.
http://reefkeeping.com/issues/2003-05/rhf/feature/index.htm
I monitored copper concentrations using a modern analytical lab technique: Inductively Coupled Plasma (ICP) using atomic emission detection. I used two different emission peaks (324.754 and 327.395 nm).
The use of multiple wavelengths was how I got a slightly better limit of quantitation than the machine qoutes (it claims 20 ppb). I could easily see a 10 ppb peak, but could not see a true peak below that. For my tank I saw clear peaks a bit bigger than the 10 ppb standard but below the 20 ppb. There was no clear peak in Instant Ocean.
My low metals article I posted above has a statement about the amount I found in my tank (10-13 ppb).
http://reefkeeping.com/issues/2003-04/rhf/feature/index.php
but at this moment I cannot find the first place I reported the copper levels in my tank and the details of doing so.
HighlandReefer
Team RC
For my clarification Randy.
These tests run for copper and the results given are for Total Copper (including organics)?
These tests run for copper and the results given are for Total Copper (including organics)?
Yes. Anything in the solution in any form gets converted into individual atoms/ions in the super high temperature of the plasma.
