PVC and Tin

[HM3105]

Hi all,

I have a question regarding PVC and what I think is called organotin.

1. On an ICP analyses, would organotin register as regular tin?

2. I read that @Randy Holmes-Farley recommended using GAC to remove organotin. I've been running cuprisorb for about a month and it hasn't helped. Would GAC remove organotin where cuprisorb would not?

3. I've read that PVC can be a source of organotin, I've always used PVC and this is the first time I've had this type of issue. The only thing that is different in this scenario is the drain lines are 3" which is the largest size I've used. It's just the standard stuff from Home Depot, I did clean it before I used it. Do DWV pipe and fittings tend to contain this compound more so than other fittings?

Other background information:

I installed a Behlen Country stock tank which is made from FDA approved LDPE. about 4 months after installing the sump I started to have corals start suffering. They had shown growth until that point though.

Since I thought it might be the new sump, I removed a couple of pieces of plastic from the sump itself, soaked it in water from a different system for a week and then sent the test sample and another sample from the same system (i.e. as a control) to ATI for testing. The sample which had been soaking with the plastic from the sump registered tin, the other sample did not.

Appreciate any and all input.

 

[Ron Reefman]

bump

Honestly, before I read your post, I'd never even heard of organotin!

 

[HM3105]

bump

Honestly, before I read your post, I'd never even heard of organotin!

Until yesterday me either. A kind reefer was helping me try to figure out where the tin might be coming from other than the sump itself.

Hoping there is a way to remove it otherwise I'm going to have to take it out and start over.

 

[HM3105]

@Randy Holmes-Farley any thoughts on how to remove it ? I've found a few places saying GAC should work. Just wondering your thoughts

 

[GoVols]

Hi all,

I have a question regarding PVC and what I think is called organotin.

1. On an ICP analyses, would organotin register as regular tin?

2. I read that @Randy Holmes-Farley recommended using GAC to remove organotin. I've been running cuprisorb for about a month and it hasn't helped. Would GAC remove organotin where cuprisorb would not?

3. I've read that PVC can be a source of organotin, I've always used PVC and this is the first time I've had this type of issue. The only thing that is different in this scenario is the drain lines are 3" which is the largest size I've used. It's just the standard stuff from Home Depot, I did clean it before I used it. Do DWV pipe and fittings tend to contain this compound more so than other fittings?

Other background information:

I installed a Behlen Country stock tank which is made from FDA approved LDPE. about 4 months after installing the sump I started to have corals start suffering. They had shown growth until that point though.

Since I thought it might be the new sump, I removed a couple of pieces of plastic from the sump itself, soaked it in water from a different system for a week and then sent the test sample and another sample from the same system (i.e. as a control) to ATI for testing. The sample which had been soaking with the plastic from the sump registered tin, the other sample did not.

Appreciate any and all input.

https://www.reef2reef.com/threads/how-would-tin-and-aluminum-be-entering-my-tank.198603/

 

[HM3105]

https://www.reef2reef.com/threads/how-would-tin-and-aluminum-be-entering-my-tank.198603/

Thank you!

I don't have a metal stand on this system. I checked all the equipment and didn't see any rusting or corroding elements.

I'm still trying to figure out if organotin is a myth or not. As @Randy Holmes-Farley pointed out there hasn't been a lot of correlation among reefers and most everyone uses PVC. If it we're present everyone should have the same issue.

I'm mostly trying to figure out if there is a way to remove it from the system. Assuming it's organotin, I think GAC should remove so I'm going to add that. If it were "normal" tin the cuprisorb I added should have removed it.

I really hope it's the PVC and it's removable. Not sure what to do otherwise. The manufacturer for the sump said they don't use any organotin stablizers when I asked.

 

[GoVols]

Randy is working with a pharmaceutical company, but comes on Reef 2 Reef most weekends.

Wish you all the best...

 

[Dkeller_nc]

"Organotin" isn't a myth, in that there are a wide variety of tin-organic compounds (the earliest one being synthesized in the mid 19th century). A particular couple of classes of organic-tin compounds are used in PVC formulations - this link will shed some light on the situation. You might note that these compounds are particularly used for flexible PVC products, so if you have any flex PVC in your system, that might be a good place to start (by removing it).

How effective GAC is going to be at removing these polar compounds from salt water is debateable. While GAC is highly effective at removing non-polar, aprotic organic compounds from salt water, and is also highly effective at removing polar organics from pure water, I'm not sure how effective it will be in the highly ionically-screened environment of salt water.

The good news is that even if GAC isn't all that effective at removing these compounds, removing the source of them and continued water changes will gradually remove them from the system.

 

[HM3105]

"Organotin" isn't a myth, in that there are a wide variety of tin-organic compounds (the earliest one being synthesized in the mid 19th century). A particular couple of classes of organic-tin compounds are used in PVC formulations - this link will shed some light on the situation. You might note that these compounds are particularly used for flexible PVC products, so if you have any flex PVC in your system, that might be a good place to start (by removing it).

How effective GAC is going to be at removing these polar compounds from salt water is debateable. While GAC is highly effective at removing non-polar, aprotic organic compounds from salt water, and is also highly effective at removing polar organics from pure water, I'm not sure how effective it will be in the highly ionically-screened environment of salt water.

The good news is that even if GAC isn't all that effective at removing these compounds, removing the source of them and continued water changes will gradually remove them from the system.

Thank you! I didn't realize flex PVC was more likely to cause an issue vs. regular PVC. I have a 4' run of flex going from the return pump to the tank.

 

[MnFish1]

"Organotin" isn't a myth, in that there are a wide variety of tin-organic compounds (the earliest one being synthesized in the mid 19th century). A particular couple of classes of organic-tin compounds are used in PVC formulations - this link will shed some light on the situation. You might note that these compounds are particularly used for flexible PVC products, so if you have any flex PVC in your system, that might be a good place to start (by removing it).

How effective GAC is going to be at removing these polar compounds from salt water is debateable. While GAC is highly effective at removing non-polar, aprotic organic compounds from salt water, and is also highly effective at removing polar organics from pure water, I'm not sure how effective it will be in the highly ionically-screened environment of salt water.

The good news is that even if GAC isn't all that effective at removing these compounds, removing the source of them and continued water changes will gradually remove them from the system.

Except the major 'source' people are worried about is PVC...... And supposedly GAC is effective at removing them...

I wouldn't remove anything - until I found out that It was causing a problem. There is no indication that it is. If I had a tank - that suddenly was daily after adding new PVC - and sent an ICP and it was high - I would check whether the level (though high) was significant. There are many other threads on here stating that there is no correlation between PVC use and tin levels - so there's that.

 

[MnFish1]

And to the OP - yes - Organotin would result in the same results as 'tin' in the ICP test. Secondly Cuprisorb may not - but GAC should remove organotin. But from what I read you havent tried that 'yet'. Lastly - As PVC becomes older - even. if it releases Tin to start - it quickly does not continue to do so (from my reading) - so I might just use GAC and watch... No panic needed

 

[HM3105]

And to the OP - yes - Organotin would result in the same results as 'tin' in the ICP test. Secondly Cuprisorb may not - but GAC should remove organotin. But from what I read you havent tried that 'yet'. Lastly - As PVC becomes older - even. if it releases Tin to start - it quickly does not continue to do so (from my reading) - so I might just use GAC and watch... No panic needed

Thank you!

 

[Makers Marc]

I dealt with this whole thing the past 6 months. Icp test showed tin at 16mcg/l on my 180g.

For two weeks I used Cuprisorb (in media bag inside filter sock wso high high flow)and GAC only, for 24/7. Test#2 came back with at 15mcg/l. So my personal conclusion is neither GAC or Curpisorb do sh1t.

Had to do several large 36-72 (20%-40%) gallon changes over the next 2 wks for levels to drop.

My tank is also 16 months old with lots of pvc.

 

[Dkeller_nc]

Thank you! I didn't realize flex PVC was more likely to cause an issue vs. regular PVC. I have a 4' run of flex going from the return pump to the tank.

MnFish1 is correct that there seems to be a weak correlation, if any, between the health of the animals in a system and the presence of elevated tin and/or aluminum. In my particularly case, I was just addressing where the likely source might be, it'd be up to you to decide whether it's truly a problem or not.

If you do decide it's an issue, I think I would definitely substitute a piece of 4' silicone tubing between your return pump and the tank before I'd remove the stock-tank sump. While silicone isn't cheap compared to PVC tubing, a 4' piece still isn't a big investment, and it's a whole lot less trouble than replacing a sump.

 

[HM3105]

MnFish1 is correct that there seems to be a weak correlation, if any, between the health of the animals in a system and the presence of elevated tin and/or aluminum. In my particularly case, I was just addressing where the likely source might be, it'd be up to you to decide whether it's truly a problem or not.

If you do decide it's an issue, I think I would definitely substitute a piece of 4' silicone tubing between your return pump and the tank before I'd remove the stock-tank sump. While silicone isn't cheap compared to PVC tubing, a 4' piece still isn't a big investment, and it's a whole lot less trouble than replacing a sump.

Thank you, I think that'll be my next thing if the GAC doesn't work.

The tin in my system started at ~80ug/l per ATI ICP. 30 days later it went to ~160ug/l. LPS and zoa's in the system aren't growing but aren't dead either. SPS added initially show normal PE but within a week have no PE and the flesh begins to receed.

I'm hopeful the GAC or WC will work. If not, the removal of the flex PVC might be next. I used PVC a lot before but never had tin issues like this so I'm just trying not to get my hopes up too high.

I appreciate everyone's input and help with this. Maybe I can avoid having to start over.

 

[Dkeller_nc]

You definitely won't have to start over - any dissolved metal can gradually be removed from a system as long as the source is eliminated and water changes and/or other removal strategies are continued. One thing to recognize, though, is that if the flex PVC in your system is the major source of tin, it's likely to continue leaching for a long time. So even if the GAC is effective at removing it from the water column, you'll have to keep employing it to keep the levels down.

 

[HM3105]

You definitely won't have to start over - any dissolved metal can gradually be removed from a system as long as the source is eliminated and water changes and/or other removal strategies are continued. One thing to recognize, though, is that if the flex PVC in your system is the major source of tin, it's likely to continue leaching for a long time. So even if the GAC is effective at removing it from the water column, you'll have to keep employing it to keep the levels down.

I may move in that direction, if the carbon is successful it'll answer the question on it being organotin. Once that happens it'll mean I know the source for sure. @MnFish1 indicated they believed that the PVC should quickly stop leeching once I begin to remove it.

 

[MnFish1]

I may move in that direction, if the carbon is successful it'll answer the question on it being organotin. Once that happens it'll mean I know the source for sure. @MnFish1 indicated they believed that the PVC should quickly stop leeching once I begin to remove it.

If I said 'quickly' - I would say that's a mistake (possibly) on my part. What I meant is that 'over time' it should become less of a problem (i.e. don't go out and replace all your PVC based on that - but instead use Cuprisorb and GAC to remove it from your tank

 

[HM3105]

Got back my most recent ICP from ATI, I'm going to post all of my ICP for this system in case anyone is interested.

ICP 2.22.19 (tin 78.48 ug/l) - //lab.atiaquaristik.com/share/d275502cf0c9ba6eac96

ICP 3.26.19 (tin 160.6 ug/l) - //lab.atiaquaristik.com/share/60dc094c295e29277a35

ICP 5.14.19 (tin 177.6 ug/l) - //lab.atiaquaristik.com/share/13e48cedba8f75a927c7

So on the plus side, the rate of increase has decreased pretty significantly. The negative is that I still don't know if that is due to the cuprisorb being added or whatever was leaching has now stopped or slowed.

The cuprisorb was added the week prior to the 3.26.19 test.

On May 12, 2019 I added 3 cups of Rox Carbon in a reactor. I'm going to let it run two weeks and send off another sample to see what effect that has.

 

[Makers Marc]

Got back my most recent ICP from ATI, I'm going to post all of my ICP for this system in case anyone is interested.

ICP 2.22.19 (tin 78.48 ug/l) - //lab.atiaquaristik.com/share/d275502cf0c9ba6eac96

ICP 3.26.19 (tin 160.6 ug/l) - //lab.atiaquaristik.com/share/60dc094c295e29277a35

ICP 5.14.19 (tin 177.6 ug/l) - //lab.atiaquaristik.com/share/13e48cedba8f75a927c7

So on the plus side, the rate of increase has decreased pretty significantly. The negative is that I still don't know if that is due to the cuprisorb being added or whatever was leaching has now stopped or slowed.

The cuprisorb was added the week prior to the 3.26.19 test.

On May 12, 2019 I added 3 cups of Rox Carbon in a reactor. I'm going to let it run two weeks and send off another sample to see what effect that has.

I may have missed it, but I take it you dont have many corals to be concerned about at this point?

I'm curious how they are reacting and/ or if that much ROX can strip other elements too much, too fast.