Yes - this was my question as well. The issue I have seen is so many people have 'unexpected' high tin levels - with no problem in their tank - I am surprised that tubing/PVC (given how they are almost universally used) - would cause problems - except in specific conditions. (i.e. perhaps tin is more toxic at certain pH, etc - or the form of the tin (organic vs inorganic - which cant be differentiated by ICP)
I appreciate this post but you left out some possibilities, like what if I’m a contrarian for kicks and only want to sound smart by finding holes in your procedure? Have you run a test for that yet?Again, the purpose of this thread was to simply report my findings from performing "ICP soak tests" on common plastic tubes from Lowes/H.D. and to suggest an inert tubing (TYGON 2475), not to claim or debate whether or not tin causes problems. Everyone can reach their own opinion on that however they wish. But for anybody that is having "tin problems" (i.e. elevated tin and corals dying) and wants to get the tin level down to zero (for whatever reason) then they may find it helpful to know what I have found regarding these commonly used plastic tubes. If the tin level is elevated and you are having coral problems and it is known that you are using plastic tubing that is leaching tin, then wouldn't it make sense to want to get rid of that tubing? There is no denying the values I found. If someone doesn't believe them, he/she can run the soak tests themselves. If someone chooses not to believe it or has elevated tin with no coral problems and/or doesn't care, then just ignore this thread.....but perhaps keep it in mind in case you ever do run into a "tin problem".
I, too, have been using plastic tubing and PVC pipes from Lowes/H.D./Ace for many years (50+) and have kept SPS successfully in many tanks. I never had tin on ICP tests from any of those tanks and never had reason to test tubing prior to my recent problem. I wonder if any of these are possibilities:
Ha ha! No, I haven't figured out a test for that yet. But there always has to be "that" crowd.
Yes. And all of my "soak tests" on PVC (3-4 tests) revealed undesirable levels (at least for a 34 gal tank) of tin leaching but not nearly as much as the plastic tubing. (There was even a little tin leaching from 2 protein skimmers and a kalk stirrer that I tested, along the same order as the PVC pipes although perhaps negligible for a large aquarium).
Or what if I'm a reefer - that appreciates the work - but doesnt completely agree with the conclusions because of the way the tests were done? Its a discussion board. Thats not 'contrarian' - thats the purpose of the forum.
" - and because he wanted to avoid tin in the salt (but it seems it would be simple to measure the salt in the ASW before and after soaking) So - I dont think pointing these things out - to the 'average person' is 'off base' - several people have already come forward 'worried' about their tanks.
Of course not everybody is having a problem with PVC. Good idea, but what would you suggest to replace it that is safe and doesn't leach tin?
That was one of the first things I tested, last May, and it came back at "zero".
From my attempts to remove tin, my anecdotal conclusions are that none of the following products were effective for removing it: Power Cleanse, Cuprisorb (likely the same product as Power Cleanse but the recommended dosage is much less for Cuprisorb), Metasorb, Polyfilter, and carbon.
The plastic tubing I discussed and tested was 3/4" and 1" pvc tubing that came with my tank and that which I purchased at Lowes/H.D. I never tested tubing from dosing pumps. I have a lot of that type of tubing, mostly silicone, but doubt that that relatively small amount of contact would be a problem. If I hadn't found such high levels of tin from the larger tubing, perhaps I would have tested the dosing tubing. If you don't use the "larger" tubing, I would consider pvc pipe or other plastics as the next most likely source(s) (and/or, even the glass).
