Any long term problens relate

[FGourdin]

I have been using lanthanum chloride in doses of 1-2 cc every 4 or 5 days to keep my phosphate level in my hundred gallon tank below .15. It has worked splendidly and I have not seen any probLems in my Chevron tang. On recent ATI ICP test I noted a concentration of 3.19 micrograms /liter of lanthanum
Is there any known complication of this chronic accumulation of lanthanum Over the long haul?

 

[Formulator]

There is unfortunately not a lot of research on the subject, but generally for most of our tank’s inhabitants it is not thought to be of major concern. However, there is significant evidence that clams are adversely affected as they enrich Lanthanum in their tissue which has been known to lead to death in long term exposure. So if you have any clams, it would be wise to find another PO4 export method.

Other than that, there are various studies that have shown at least that lanthanum is not completely inert in our aquariums as was once thought, and many animals utilize Lanthanum and other rare earth elements/lanthanides in biological processes. A practical limit or specific toxicity level has not really been established, but the elements have been measured in healthy marine animals’ tissue at concentrations in excess of 500-1000 ug/kg, which leads me to believe your 3 ug/L is nothing to be concerned about. Here is an interesting chart from that paper showing Lanthanum (La) and other rare earth elements (REEs) measured in tissues of various marine organisms relevant to our hobby.

If you are up for an interesting technical read, this is a great review of current knowledge on the subject and directions for future research:

Neira P, Romero-Freire A, et. al. (2022) Review of the concentration, bioaccumulation, and effects of lanthanides in marine systems. Front. Mar. Sci. 9:920405.

 

[FGourdin]

There is unfortunately not a lot of research on the subject, but generally for most of our tank’s inhabitants it is not thought to be of major concern. However, there is significant evidence that clams are adversely affected as they enrich Lanthanum in their tissue which has been known to lead to death in long term exposure. So if you have any clams, it would be wise to find another PO4 export method.

Other than that, there are various studies that have shown at least that lanthanum is not completely inert in our aquariums as was once thought, and many animals utilize Lanthanum and other rare earth elements/lanthanides in biological processes. A practical limit or specific toxicity level has not really been established, but the elements have been measured in healthy marine animals’ tissue at concentrations in excess of 500-1000 ug/kg, which leads me to believe your 3 ug/L is nothing to be concerned about. Here is an interesting chart from that paper showing Lanthanum (La) and other rare earth elements (REEs) measured in tissues of various marine organisms relevant to our hobby.

If you are up for an interesting technical read, this is a great review of current knowledge on the subject and directions for future research:

Neira P, Romero-Freire A, et. al. (2022) Review of the concentration, bioaccumulation, and effects of lanthanides in marine systems. Front. Mar. Sci. 9:920405.

There is unfortunately not a lot of research on the subject, but generally for most of our tank’s inhabitants it is not thought to be of major concern. However, there is significant evidence that clams are adversely affected as they enrich Lanthanum in their tissue which has been known to lead to death in long term exposure. So if you have any clams, it would be wise to find another PO4 export method.

Other than that, there are various studies that have shown at least that lanthanum is not completely inert in our aquariums as was once thought, and many animals utilize Lanthanum and other rare earth elements/lanthanides in biological processes. A practical limit or specific toxicity level has not really been established, but the elements have been measured in healthy marine animals’ tissue at concentrations in excess of 500-1000 ug/kg, which leads me to believe your 3 ug/L is nothing to be concerned about. Here is an interesting chart from that paper showing Lanthanum (La) and other rare earth elements (REEs) measured in tissues of various marine organisms relevant to our hobby.

If you are up for an interesting technical read, this is a great review of current knowledge on the subject and directions for future research:

Neira P, Romero-Freire A, et. al. (2022) Review of the concentration, bioaccumulation, and effects of lanthanides in marine systems. Front. Mar. Sci. 9:920405.

Thank you so much for your thoughtful, science based answer!