Tin, toxic levels?

[maroun.c]

Any idea at what levels Tin is considered to be toxic for corals? Any documented different levels intolerance for different corals?
Thanks.

 

[nautical_nathaniel]

#reefsquad, does anyone have any info on this topic?

 

[Dr. Reef]

its a very broad question. Tin (Sn) which is metal is not primarily found in seawater or our tanks. in Saltwater its in Sn(OH)4 form.
Tin has many forms and without knowing which form its in, its hard to say if its toxic.
Tin will mostly bind to organics in saltwater and binding will reduce its toxicity.
Most of the results in ICP testing of our water sample is merely noise and i wouldnt be too worried about it as it can also be in the glass.

I have seem reefers reporting Sn of 30ug/l having negative effects on corals and some as low as 10.

 

[Cory]

its a very broad question. Tin (Sn) which is metal is not primarily found in seawater or our tanks. in Saltwater its in Sn(OH)4 form.
Tin has many forms and without knowing which form its in, its hard to say if its toxic.
Tin will mostly bind to organics in saltwater and binding will reduce its toxicity.
Most of the results in ICP testing of our water sample is merely noise and i would be too worried about it as it can also be in the glass.

I have seem reefers reporting Sn of 30ug/l having negative effects on corals and some as low as 10.

Probably the difference in sensitivity can be related to chelation by organics.

 

[Randy Holmes-Farley]

There is not, and really cannot be, definitive info on the exact values of tin that are an issue because none of us knows the form of tin present in our reef tanks. It's like asking how toxic is carbon. In the form of cyanide it is very toxic, in the form of glucose, not so much.

As noted above, about all you can do is note what other reefers observe and hope that your type of tin is similar to theirs.

In that vein, 30 ug/l seems to be about in the middle between those that have issues that they attribute to tin( rightly or wrongly) and those that have no apparent issues.

 

[Randy Holmes-Farley]

Probably the difference in sensitivity can be related to chelation by organics.

That would be a big part of differences, although not the only one. Different oxidation states can be present too. Sn++, Sn++++, etc. Organotin compounds (containing a direct tin-carbon bond) might be the worst as they are known to be highly toxic and have been used to prevent fouling of ship hulls.,