Tin

BradB · Sep 3, 2019

Can you share anything about Tin, what levels are toxic in reef tanks, where it might come from in a reef tank, how to test for it, and how to remove it?

I posted several threads about a near total wipeout of my coral. I just got my ATI results back, and while copper (which I suspected) is over 8 times NSW, Tin is elevated more than 54 times normal!

https://lab.atiaquaristik.com/share/a9f1c254206935e18bd9

This is confusing, as while there is plenty of copper around the tank that shouldn't come in contact with water, tin shouldn't be present in any form anywhere around the tank. I did google, and see several people talk about magnets, but don't understand why anyone would intentionally add Tin to either neodymium or ferric magnets.

Tin from solder should show elevated Zinc as well, right?

Since I continually run cooprisorb, shouldn't my copper be undetectable? Is it possible I still have a bigger problem with Copper than Tin being added, but I am just better at removing copper?

Other than a small amount of Silicon, my RO results are perfect.

Schnizzle · Sep 3, 2019

I had tin, copper, chromium and zinc in my tank. I ran a magnet (wrapped in a plastic baggie) through the sand and found a bunch of rust and a dime sized flake of rusty metal. Ran cuprisorb and weekly 30% water changes for 6 weeks to get levels back down to satisfactory.

BradB · Sep 3, 2019

On rereading, my results are not 54 and 8 times NSW values - they are 54 and 8 times ATI's reference values, which are largely arbitrary.

Lots of people are reporting high Tin, but very few are actually quantifying this, and the numbers are all over the place. I have no idea if 25.94ppb is absolutely lethal or just the "normally elevated over NSW" as many of us have. 4ppb Copper seems closer to "normally elevated over NSW".

If Tin is my problem, it doesn't seem to fit with my tank scenario of sudden massive die off and gradual recovery. If I had rusty metal in the tank, things would gradually get worse. I wouldn't see perfectly healthy reef suddenly crash, and I certainly wouldn't see gradual recovery without the problem being fixed.

BradB · Sep 3, 2019

I did have a Triton test just under 4 years ago that reported undetectable Tin. I know that is a long time ago, but I have not changed much equipment. That doesn't rule out something in the tank 4 years ago that only recently corroded, but seems to rule out things like PVC pipe.