Elevated tin, organotin from pvc?

[Righteous]

So my triton test came back today and is showing elevated tin levels. Other parameters look good (aside from lithium, which everyone seems to have). The tank is a new setup about 7 months old with livestock from a previous tank. A sump was added 3 months ago with some new PVC. Equipment is new, and no rusting or exposed parts.

Two separate attempts to keep cleaner shrimp failed, with both dying within two weeks. Most snails added to the tank perish in a month or two. I have no idea if the levels of tin reported (~8ppb) could be enough to cause such effects.

So is there any solution other than water changes? Has anyone had success overcoming elevated tin levels? Also in the future, what options do we have, if any, to replace PVC if it is really leaching organotins into the water?

I found this EPA study from 1982 outlining organotin leaching from PVC. The chart on page 8 seems to indicate levels of ~1-35ppb for various organotins over a week of time.

http://nepis.epa.gov/Exe/ZyNET.exe/...ge&MaximumPages=1&ZyEntry=1&SeekPage=x&ZyPURL

Triton results:

 

[Randy Holmes-Farley Verified Community Expert]

I don't know if the tin that some folks see is more likely to come from PVC, or from other places, such as corroded metal parts of lighting, etc. When I did some online surveys in the past year, I didn't really find much correlation between tin and PVC use.

New PVC pipes are a lot more likely to be a source than are those that have been in a tnak for an extended period, since any leaching will slow down considerably over tiem.

GAC is likely a good way to take organotin compounds from the water, as might Purigen. If it is ionic tin from corroded metal parts, that may be different and likely won't bind to GAC unless it is attached to organics first.

 

[Righteous]

I did come across that survey, which is what led me at researching the organotin and pvc route. The current poll says 41% have tin and new pvc. Not sure if that counts as a correlation. I know tin is in solder, but it seems otherwise uncommon for so many people to have it elevated.

I've been running GAC, replacing monthly. I'll try running purigen as well and see how it goes. Thanks for the suggestion.

The current literature seems to indicate that organotin does indeed leach from pvc. There's a number of references to it as can be seen here. At least one mentioned that it's variable based on manufacture.

https://scholar.google.com/scholar?hl=en&q=organotin+pvc&btnG=&as_sdt=1,33&as_sdtp=

 

[Randy Holmes-Farley Verified Community Expert]

Yes, I don't doubt some leaches (when it is present), I'm just not sure it is the explanation for the levels reefers see (especially for folks who do not have rigid PVC, obviously).