Can Ceramic Rock Leach Tin (Sn)?

VJV · Sep 22, 2017

Hi, for the longest time my reef had perfect parameters for Calcium, All, Magnesium (and all others according to recent Triton tests) but acros have always struggled. They would hold for about a month and than they would slowly loose colour and eventually die. My nutrient levels have always been at zero (Hanna ULR Phosphorus and Salifert NO3) but what I have found in the Triton tests to be very high was Tin (Sn).

The levels were at 4,75 which is apparently too high.

I have found a rusting magnet from a Innovative Marin Gourmet Defroster which I have since removed, and may account for the decline in Sn levels to 3,49. However, this is a piece of equipment that is only occasionally in the tank and the issues with acro STN have been going on since before I used it. I have now stumbled upon the below article and wonder whether my ceramics could also be leaching Sn:

"The major commercial applications of tin are in tinplate, solder alloys, bearing metals, tin and alloy coatings (both plated and hot-coated), pewter, bronzes, and fusible alloys. In its chemical reactions, tin exists in two valence states (II and IV) and is amphoteric (able to react as both an acid and a base). In addition, it can link directly with carbon to form organometallic compounds. These properties have given rise to many important uses for tin chemicals—for example, in electroplating, agricultural and pharmaceutical products, and plastics and ceramics."

I have always used ceramic rock from a French company called "Aquaroche" and it is what I have in my system. Could the Tin be coming from those rocks?

Randy Holmes-Farley · Sep 22, 2017

I could only answer, maybe. It is possible either the magnet or the ceramic could be the source, but I do not know.

VJV · Sep 22, 2017

Thanks [emoji106]. Just got a reply from Triton saying that they have tested Aquaroche in their lab extensively and found that it did not leach anything that could create problems in a tank. The tests took several months apparently and the rock was even broken into pieces and acid bathed and still nothing noticeable leached. I guess that is good info for anyone using these rocks (more likely in Europe).

VJV · Sep 22, 2017

Would you consider those levels of Sn toxic? Since they came down my actos are doing much better and growing so I guess at least at 4,75 clearly they were not acro friendly. Another thing that does not last long in my tank, in spite of all the acclimation are snails... perhaps also linked to high SN...?

A. grandis · Sep 22, 2017

When looking into something like that we need to consider other facts too..
As we know the combo of things could actually be the culprit.
Light, temp., lack or excess of additives, predators, salt, lights, even the simple presence of certain algae could do the trick...
Very interesting, though.
Good luck!
Grandis.

rkpetersen · Sep 22, 2017

Oddly enough, the tin in my first sample sent to Triton was also quite elevated, higher than yours, reading 11 ppb. I traced this to an almost-new return pump with metal hardware that was already rusting. Replaced the pump, and tin went to zero very quickly (I routinely use GAC and PolyFilter, fwiw). Was this level toxic in any way? VERY hard to say. While some of my corals were suffering at that time, iodine and strontium were also elevated; of the 3, seems like iodine was the most likely to be causing what I was seeing (photosensitivity, bleaching). What would you even look for in the case of aquatic tin poisoning? Perhaps the 'dwindles', as OP experienced with his acros.

A. grandis · Sep 23, 2017

Is GFO a source of tin?
Possibly, I would think.
Grandis.

PiscesPower · Sep 23, 2017

rkpetersen said:
Oddly enough, the tin in my first sample sent to Triton was also quite elevated, higher than yours, reading 11 ppb. I traced this to an almost-new return pump with metal hardware that was already rusting. Replaced the pump, and tin went to zero very quickly (I routinely use GAC and PolyFilter, fwiw). Was this level toxic in any way? VERY hard to say. While some of my corals were suffering at that time, iodine and strontium were also elevated; of the 3, seems like iodine was the most likely to be causing what I was seeing (photosensitivity, bleaching). What would you even look for in the case of aquatic tin poisoning? Perhaps the 'dwindles', as OP experienced with his acros.

Do you mind saying what brand of return pump you had the issue with? My tin, on my first Triton is a bit high, just curious.

Just noticed you are also in the Seattle area. Hello from Renton!

VJV · Sep 23, 2017

Well, my first return was a Vectra L1 (which I am extremely disappointed with but that is for another thread). Oddly enough, not long after I installed it I noticed the outside of the pump was covered in specs of rust. I opened it up but could not find any rusting parts so just left it.

A couple of months later I could no longer stand how loud the pump was (looked like a jet turbine) and sent it to the distributor. They told me (2 months later) that the noise was normal and I just replaced it a while back.

VJV · Sep 23, 2017

Triton told me that they have tested Aquaroche ceramics in their facilities extensively and found no toxic components leached. Apparently the test took several months and the rocks were broken into pieces and acid bathed. This is good info for anyone that uses Aquaroche (I suspect only in Europe)

andrew james · Sep 23, 2017

I had high tin as well and I still dont know what the cause was. My solution which I still employee is to run 6 tablespoons of Cuprisorb in a reactor with carbon. It's completely solved my tin problem and I havent had an STN/RTN since.

VJV · Sep 23, 2017

That is great info! I will give that a go. I thought I read in other threads that nothing would remove Tin but since I have Cuprisorb once the new Triton results are in I will give it a go.

Randy Holmes-Farley · Sep 23, 2017

VJV said:
Would you consider those levels of Sn toxic? Since they came down my actos are doing much better and growing so I guess at least at 4,75 clearly they were not acro friendly. Another thing that does not last long in my tank, in spite of all the acclimation are snails... perhaps also linked to high SN...?

I'm not sure. Could be. Even if we had good data available (we don't), one can't really judge the toxicity of trace metals by concentration alone since there are several different chemical forms and they can all be bound to organics that alter the toxicity.

rkpetersen · Sep 23, 2017

PiscesPower said:
Do you mind saying what brand of return pump you had the issue with? My tin, on my first Triton is a bit high, just curious.

Just noticed you are also in the Seattle area. Hello from Renton!

It was a Jebao. Sorry I don't recall the exact model, but it was a relatively recent one, had exposed steel screws. I think the most recent Jebao pumps have fixed this and other issues, but I'm probably not going to use them again.

If you're in Renton, we've probably run into each other at Barrier Reef; I'm in there all the time.