Lanthanum Chloride vs Cerium Chloride (My Fish Are Dying)

[Ben Pedersen]

The element, Cerium, has 2 stable oxidation states, +3, and +4. So you will either have Cerium trichloride, or Cerium tetrachloride, which is also toxic. Here is the MSDS for CeCl4 https://fscimage.fishersci.com/msds/04387.htm

Heptahydrate just means there are 5 water molecules for every CeCl4 in the crystal matrix. When it dissolves it just becomes part of your aquarium water and has no effect on the properties of the compound in solution.

Also, there is only 1 stable isotope of Cerium, which has an 88% natural abundance, so it's definitely possible there could be some radioactivity going on as well. Although judging by the extremely long halflife of the most common radioactivity isotope, it probably isn't super radioactive.

I would just stay away from heavy metals in general.

Thanks for the info.. Clearly Cerium should not be used.. Wish the manufacture would have updated the spec sheet.

 

[Ben Pedersen]

Thank you all for the feedback and support.. Here is my tank right now..

 

[Dkeller_nc]

I completely agree.. So much is un known and not really testable regarding full and patial reactions and by products. In this case the manufacture changed the formula of the product from lanthanum chloride to cerium chloride because cerium bonds to phosphate quicker then lanthanum. Aperently the toxicity for cerium is much higher for marine fish as compared to fresh water fish.

In regards to my situation, I added .03 mL to my skimmer... I had high phosphates.... so I think that all or almost all of the cerium was rendered inert. However, the manufacture said that there were other harmless salts as a byproduct of the manufacturing process in the product as well. There is no way to really know what killed the fish.. This product is obviously not safe for marine use. I just wish the manufacture had updated the spec sheet identifying that it was Cerium based.

Ya.. this is the biggest fish loss I have ever had.. Been reefing for 38/39 years... that tank is 10+ years old.. the chromis have been there for over 8 years.. and the other fish for many years..

A strange coincidence... All the fish that died were the most aggressive fish (bosses) Powder Brown Tang, Female Bird Wrasse, Lemon Peal Angle.. except for the Foxface.

Very sad.. almost made me cry to see the male bird wrasse lay down next to the female.. Now he is swimming around recognizing that the female is missing.

One other comment about my speculation (and it is precisely that - unresearched, pure speculation) about "excess" cerium and/or lanthanum not precipitating with anions other than phosphate in marine tank water and being bio-available to cause toxic reactions in marine creatures. Randy has written fairly extensively on the fact that reef tank water is well above the expected saturation point for calcium and carbonate ions and the reason this excess isn't immediately precipitated out of the tank water is the presence of the magnesium ion that poisons growing crystal surfaces of calcium carbonate and dramatically slows down abiotic precipitation of calcium carbonate.

I'm wondering if there are similar complexities in the chemical makeup of reef tank water that could slow down what would otherwise be the almost instant precipitation of solid (and insoluble) lanthanum phosphate in a solution that contains a stoichiometric ratio of lanthanum and phosphate ions.

There certainly seems to be anecdotal evidence that some users of lanthanum chloride for phosphate removal experience zero toxicity issues with their fish or other creatures, while others report substantial problems, even though on the surface, their tanks are very similar in terms of water chemistry and the species present.

 

[Randy Holmes-Farley]

Thanks for the info.. Clearly Cerium should not be used.. Wish the manufacture would have updated the spec sheet.

The info posted by him is factually incorrect, so I would not pay attention to it.

Cerium is perfectly stable with respect to radioactive decay, and cerium IV chloride is not a thing.

heptahydrate means 7 water molecules, not 5.

The MSDS he posted is not for cerium IV chloride.

 

[Dkeller_nc]

On the slightly off-topic commentary about the fate of lanthanum and/or cerium chloride added to tank water and whether it is "completely used up" by precipitation with phosphate and/or other ions, it does appear that both lanthanum and cerium carbonates are nearly insoluble in water. Obviously, there's a boatload of carbonates in reef tank water, so there would certainly be enough present to form insoluble lanthanum/cerium carbonate with any reasonable dose of the chloride forms, regardless of the amount of inorganic phosphate present.

However, that's equilibrium chemistry, and while that matters, kinetics are also important. The catch is that I've no particular information about how quickly lanthanum/cerium carbonate would form if a solution of the chloride form is added to marine tank water.

 

[Ben Pedersen]

The info posted by him is factually incorrect, so I would not pay attention to it.

Cerium is perfectly stable with respect to radioactive decay, and cerium IV chloride is not a thing.

heptahydrate means 7 water molecules, not 5.

The MSDS he posted is not for cerium IV chloride.

Just was being polite... Letting him sound smart...

 

[Ben Pedersen]

On the slightly off-topic commentary about the fate of lanthanum and/or cerium chloride added to tank water and whether it is "completely used up" by precipitation with phosphate and/or other ions, it does appear that both lanthanum and cerium carbonates are nearly insoluble in water. Obviously, there's a boatload of carbonates in reef tank water, so there would certainly be enough present to form insoluble lanthanum/cerium carbonate with any reasonable dose of the chloride forms, regardless of the amount of inorganic phosphate present.

However, that's equilibrium chemistry, and while that matters, kinetics are also important. The catch is that I've no particular information about how quickly lanthanum/cerium carbonate would form if a solution of the chloride form is added to marine tank water.

Very possible there are inhibitors. I have not looked for literature describing these process.. but know any experiments would have been done in controlled environments with all knowns. Our tanks have so many variables (unknowns) making it impossible to know. I sounded a little bit like Donald Rumsfeld there.

I'm still curious the mechanism that cause the fish ill affect.. Who knows, maybe Cerium Chloride has som affinity to a component of the fish gill or blood (like hemoglobin and carbon monoxide)... Is there some component in a fish gill apparatus that has a free phosphate molecule? All I know is that the fish were heavy breathing for 3 days and now better.. Just glad the affect was not permanent.

 

[Dkeller_nc]

Good to hear that the survivors are better, and that the effect was temporary.

Thought a little more about this, and it occurred to me that figuring out whether there's any residual soluble lanthanum/cerium in tank water after a treatment is now possible and within reach of a hobbyist, with a couple of "ifs" as conditions. No doubt about it, but detecting and quantifying any lanthanum/cerium in an aqueous sample would require ICAP. That's a technology that would've been prohibitively expensive for a hobbyist to do some experiments on this subject 15 years ago, but is now pretty commonplace.

The way I'd do this is to get several samples of tank water of around a gallon each, test the samples for inorganic phosphate, add a quantity of lanthanum chloride that's well below the stoichiometric ratio with the phosphate level, a quantity that's about a 1:1 stoichiometric ratio, and one that's well above the stoichiometric ratio, such as 4 to 1.

Allow the resulting precipitate to fall to the bottom of the container, draw off the samples necessary for ICP testing, then filter them through the finest syringe filter easily obtainable (such as a 0.1 micron absolute cutoff syringe filter). Ship these off to an ICP lab and have them tested for lanthanum. The "ifs" involved are whether or not one could find an ICP lab that will test a sample for lanthanum, and the other "if" is whether or not there would be slow precipitation of lanthanum and another component of the seawater other than phosphate. If the last "if" is true, then there's a possibility that the lab will report zero soluble lanthanum, since most will have precipitated by the time the analysis is performed and most labs would presumably filter samples going into their machine to protect the equipment. One way to take care of that last "if" that would give a more complete picture but at a higher cost would be to split the filtered samples in half, and submit one as-is, and one that's been acidified with nitric acid, which would keep any lanthanum in solution.

 

[Randy Holmes-Farley]

There are folks who report lanthanum by ICP, but I do not know the accuracy of the measurements.

Excess Lanthanum

I dose Lanthanum Chloride to manage phosphate. I am having some trouble with corals and a Triton test came back with very high levels of Lanthanum. I currently dose into my Rollermat, but maybe that is not catching enough precipitate? Or is this different because it’s dissolved? How can I stop...

www.reef2reef.com

 

[Dkeller_nc]

Yeah, that's certainly a concern. I honestly have no idea what these labs use as standards. Presumably, they're only measuring lab-made standards with just a few elements of interest to hobbyists, and precisely how often they do this to ensure their calibration curves remain accurate is anyone's guess. Could be wrong about this, but I doubt they're using rare-earth standards to generate calibration curves for those elements.

 

[Ben Pedersen]

I was just reading the other day that there is a testing facility in Switzerland that will test for rare-earth elements.. But as was mentioned, the sample would continue to precipitate while in transit. And darn.. I just ran out of nitric acid...

In our aquariums, I would think that there are other variables that may speed up or slow down the process.. so that even if you found in a controlled lab condition that there was or was not remaining agent... in an aquarium setting, the results may be different (depending on how the agent was administered, the quantity administered, the variety of salt used to make the water, how long since the saltwater was made, the concentration of phosphate in the water, the tank substrait, the temperature, if a protein skimmer was running, if GAC or other was being used, etc).

In my case, After several water changes and running carbon and zeolite.. it would be too late to try such a test even if I had not just run out of nitric acid.

 

[Ben Pedersen]

Very interesting, any theory as to how this condition impacts fish?

 

[Christoph]

Hello Randy,

Lanthanum has very "bright" emission lines that are not interfered by other elements, making ICP-OES a very sensitive technique for it. Our limit of detection is around 0,5 ppb (µg/l).

We however do not test for cerium in our standard sequences - but cerium is also highly sensitive in ICP-OES. When there is the requirement (and i didnt see it until i was reading this thread) it is possible to also routinely test for cerium.

Best regards,
Christoph

 

[Randy Holmes-Farley]

Thanks, Christoph.

 

[Dkeller_nc]

I was just reading the other day that there is a testing facility in Switzerland that will test for rare-earth elements.. But as was mentioned, the sample would continue to precipitate while in transit. And darn.. I just ran out of nitric acid...

In our aquariums, I would think that there are other variables that may speed up or slow down the process.. so that even if you found in a controlled lab condition that there was or was not remaining agent... in an aquarium setting, the results may be different (depending on how the agent was administered, the quantity administered, the variety of salt used to make the water, how long since the saltwater was made, the concentration of phosphate in the water, the tank substrait, the temperature, if a protein skimmer was running, if GAC or other was being used, etc).

In my case, After several water changes and running carbon and zeolite.. it would be too late to try such a test even if I had not just run out of nitric acid.

I was just musing about this question in general (is there remaining unprecipitated, solubilized lanthanum/cerium after dosing for phosphate removal). In my opinion, it would be a useful prospective experiment for the reefing community from the standpoint of using (perhaps extreme) caution about dosing lanthanum chloride for phosphate removal, especially with respect to the quantity of lanthanum chloride used versus the phosphate concentration in the tank water.

I was also speculating about the mechanism for lanthanum toxicity, particularly with respect to tangs. Like Randy, I have some mechanistic doubts about excess precipitated lanthanum phosphate particles that should be utterly insoluble in a marine environment being the actual cause of toxicity to fish. However, dissolved lanthanum that remains in the water column after a phosphate removal treatment does make some logical sense with respect to fish loss, particularly for high-metabolism fish like tangs.

On a personal basis, I choose to use GFO for phosphate removal as I'm quite leery about dosing anything into my tanks. And generally, I use GFO very, very rarely - typically only when I've had a significant loss or tank upset that's put a lot of nutrients in the water.

With respect to phosphate level, I'm also quite skeptical about the utility of "100 ppb" rule-of-thumb as an optimal level for SPS tanks. That skepticism is based on my personal tanks, which often run well in excess 100 ppb inorganic phosphate, as well as others that have published details of their tanks that are routinely run as high as 1 - 3 ppm of inorganic phosphate, such as Richard Ross.

 

[Ben Pedersen]

I was just musing about this question in general (is there remaining unprecipitated, solubilized lanthanum/cerium after dosing for phosphate removal). In my opinion, it would be a useful prospective experiment for the reefing community from the standpoint of using (perhaps extreme) caution about dosing lanthanum chloride for phosphate removal, especially with respect to the quantity of lanthanum chloride used versus the phosphate concentration in the tank water.

I was also speculating about the mechanism for lanthanum toxicity, particularly with respect to tangs. Like Randy, I have some mechanistic doubts about excess precipitated lanthanum phosphate particles that should be utterly insoluble in a marine environment being the actual cause of toxicity to fish. However, dissolved lanthanum that remains in the water column after a phosphate removal treatment does make some logical sense with respect to fish loss, particularly for high-metabolism fish like tangs.

On a personal basis, I choose to use GFO for phosphate removal as I'm quite leery about dosing anything into my tanks. And generally, I use GFO very, very rarely - typically only when I've had a significant loss or tank upset that's put a lot of nutrients in the water.

With respect to phosphate level, I'm also quite skeptical about the utility of "100 ppb" rule-of-thumb as an optimal level for SPS tanks. That skepticism is based on my personal tanks, which often run well in excess 100 ppb inorganic phosphate, as well as others that have published details of their tanks that are routinely run as high as 1 - 3 ppm of inorganic phosphate, such as Richard Ross.

I completely agree.. In my experience, prolonged phosphates levels around and above 0.4 ppm result in red turf algae... Doubled my food for the fish because the Powder Brown was harassing the other tangs. No longer...

All fish have completely recovered. Did finally find the dead lemon-peal and got it out... thank the Lord.. Removed a 12" in diameter birds nest..

Here is my tank right now:

 

[Dkeller_nc]

That's a really nice tank. Quite different than the more typically seen fluorescent stick farms. And I'm guessing that it's quite large judging from the relative size of the emperor angel. My hat's off to you - I've been doing this for about 3 decades now, enough to know that "fixing" a small tank (<50 gallons) is pretty easy and relatively cheap - just change out 30% or more of the water. That gets progressively more difficult to do as you get larger than 50 gallons, not to mention a lot more expensive.

 

[Ben Pedersen]

That's a really nice tank. Quite different than the more typically seen fluorescent stick farms. And I'm guessing that it's quite large judging from the relative size of the emperor angel. My hat's off to you - I've been doing this for about 3 decades now, enough to know that "fixing" a small tank (<50 gallons) is pretty easy and relatively cheap - just change out 30% or more of the water. That gets progressively more difficult to do as you get larger than 50 gallons, not to mention a lot more expensive.

Thank you for the kind words.. It isn't that big.. but am setting up a 300+ right now. I really cant believe I have been doing this for 38+ years. I have loved the ocean and reefs since I was a little kid.

All the fish are doing great now.. but have had a few corals RTN since the issue. Not sure if it was from the dead fish in the water for a couple days or something else. More water changes.

 

[drawman]

Very sorry for your losses Ben but also glad to hear things are rebounding.

 

[Ben Pedersen]

Very sorry for your losses Ben but also glad to hear things are rebounding.

Hopefully all the coral will be ok... probably issues caused by having a dead 8" wrasse, and 4.5" lemon-peal in the tank for 2 days. Thank the Lord I finally found them and was able to get them out.