Dr Jim,
excellent work, thanks for conducting and financing this study on your own to find out the source of tin in your reef tank. Your corals will thank you, any many other reefers will benefit from your work that are searching for mysterious tin sources.
If youll ever find yourself in such a "hunt" again: Let me know, we will analyze those samples free of charge due to the huge benefit for the hobby of such experiments.
Best regards,
Christoph
Thank you, Dr. Denk, for your generous offer!
For those that do not know about Dr. Denk’s ICP Lab (OCEAMO) you can read about it here:
Recently, Dr. Christoph Denk, a chemist, research engineer, and founder of OCEAMO contacted me after reading about my “tin problem” on a R2R thread. He generously offered to run 10 ICP tests for me for free for which I am most grateful. (I posted new comments on my “tin thread” here...
www.reef2reef.com
I recently received 10 ICP test results from OCEAMO that Dr. Denk ran for free for me to help me further solve my tin problem. Controls were submitted for each of the samples where water that was used for the “soaks” was tested before the soak was initiated. Of interest are the following results:
- I repeated the “soak test” with the “green tube” but this time in 2 gal saltwater, without circulation, for 7 days. The ICP result was 111.6 which is only 7.7% of the original test value, but certainly still significant. I suspect the difference is due to the fact that saltwater was used this time….(RO/DI water is more “reactive” and IMO would be more likely to “draw out” the tin); and, no circulation through the tube was used this time.
- I tested a white PVC pipe (intended for Home Central Vacuum System) that I used temporarily as a drain to my sump when I found elevated tin from the Red Sea Sched. 80 drain pipe. 4 gal of RO/DI was used for 1 month and the Tin came back at 360.8. This appeared worse than the original Red Sea drain pipe so I put that one back on!
- Since Jack Kent (CEO of Continuum) sent me a free bottle of POWER CLEANSE, I decided to perform a “crude” experiment to see if this product can remove tin, thinking he would be interested. I placed 4 ml of Power Cleanse in 946 ml of the water from #1 above (i.e. the sample that the “green tube” was soaked in). This would extrapolate to twice the recommended dosage. I simply shook the bottle several times a day for 2 days, then took a sample. Although running water through a media bag would have been a better option, I would have expected some decrease in the tin from what I did. But unfortunately, the tin came back at 107.6; the original sample before adding the Power Cleanse was 111.6 so the decrease was probably not statistically significant. (Jack told me that if a product was to be successful removing tin, it should be apparent after just 24 hrs; I allowed 48 hours).
These tests will conclude my tin saga. My level is now down to
14 which suggests I am going in the right direction now that I eliminated the green tubing. (I am still awaiting a response from Red Sea).
The following are some of my “gut” feelings about my thoughts regarding tin, (after 45+ ICP tests), presented in two categories:
A. Comments for which I have a STRONG suspicion:
1. Most plastics (PVC pipes; tubing; skimmers; reactors) very likely leach tin, especially when new.
2. Tin problems are probably less common in large-volume tanks (> about 100 gal).
3. Rock adsorbs tin and can release it (which may lead to faulty conclusions when trouble-shooting a tin problem).
4. Different corals probably have varying degrees of susceptibility to elevated tin levels.
5. If tin is the only heavy metal elevated on the ICP test, then the tin is probably coming from plastic rather than a corroding piece of metal.
B. Comments for which I have suspicion but with less evidence:
1. For many corals, tin levels up to 20-30 may not be especially harmful although obviously not desirable. The tin level at which a coral suffers is probably related to other concurrent negative factors, (i.e. the more stable the system and the healthier the coral to begin with, the greater the level of tin it may be able to tolerate).
2. Popular media used for removing Cu and other heavy metals may not be very effective for tin. This seems to be the case for Power Cleanse, and if so, then probably also SeaChem’s Cuprisorb which is probably the same product (according to Jack Kent). (Note that none of the products being used for attempted tin removal are labeled for this use).
3. Release of tin from plastics probably gradually subsides but may take more than a year to reduce to negligible levels.
4. If an ICP test reveals tin, it is probably a true value; however, it may be prudent to retest with the same or a different company before panicking and taking drastic measures.
5. It may be prudent to soak or run any new reactors or plastic items in a bucket of RO/DI for a day or two when possible. However, IMO, probably only a small, perhaps negligible, amount of tin will be removed in such a short time. (RO/DI probably “draws” out more tin than saltwater would).
Just hope that you never have a tin problem!
