FYI - GE Silicone II - TOXIC

jpkrze

New member
Just wanted to put this out there as an FYI.

DO NOT USE GE SILICONE II (black)

I had 12 fish die within 48 hrs. Never seen fish die soo fast or one after another. Used this to attach a 3d background in my 185g and it killed the entire tank.

Some people say this stuff is ok to use but I would steer clear! Just my 2cents.

Hope this post saves you some time and $$.
 
Did yours have the mold/mildew inhibitor?

It's not that I don't trust you, but I have to ask since people have been using the GE II for a long time on various projects in/around reef tanks w/ no problem.
 
I like a bit more info as well...

Cure time?
Was this windows and doors or bathroom?
How do you know for a fact it was the silicone?

Thanks
 
Gluing a background on seems to imply a really major change in the system, i.e. practically starting it from scratch since I suspect it would be empty when you did the gluing. Can you describe your entire process?
 
I used GE II windows & doors that never mentioned any mold inhibitors on a foam background as well. After about a week i added a pair of snails (strombus maculatus). I think they died overnight (i had put them with a small piece of algae wedged into a rock next to them). Luckily (for me, not the snails) i have enough of them breeding that losing snails isn't really a concern. I completely changed that water out and mixed up a new batch (only 10g, no big deal) and did it again. This time the snail lived a couple of days i think. So far, i have had maybe 5 die and none survive more than 3 days i think.

I actually read, later, that it cured with ammonia, but as i tested the water it was never present...

The only other thing i could think of is that the foam i used was doing it, its Smartpond Foam Sealant. No epoxy or anything on it after that.

I have another snail in the tank at the moment going on its 3rd day...

I also thought about pulling the panels out and using just plain silicone, but i don't know if that is even possible with all the stuff i used to attach them. Plus getting the old stuff off the panels would probably be very hard.
 
It was the Window and Door Silicone II in black. Not the bath one that list 5yrs mold free etc. Cured for 3days. These were also freshwater cichlids which are much more hardy than my reef fish. Yes, it was a large water change but all the filters were still full/warm from an established tank. These fish were acting weird, like they were on drugs or something. Never seen anything like it. The background was from Universal Rocks and I've never heard of anyone having a problem with those.

I also read Silicone II produces Ammonia when curing but tests came up 0. Ran carbon as soon as the first fish dropped. Leads me to guess some chemical is poisoning them. My question is does the poison ever stop or will it keep leaching out unless I tear it down.
 
reeading this is making my want to pull my hair out! i just built the thing! i was told it was fine and used before


Relax sparky :rollface:

Im not sure how far in the process you are but proceed with a little caution and all should be fine. If all is still dry I would give a bit more time to cure than originally thought. I will tell you there are many many people that have used this stuff with no issues, including myself. In this case, the addition of something as large as a background might have a been a large contributor to his issue, its hard to say. Im drilling my tank tonight and will be siliconing my glass holes overflow in next couple days, I have no issue using this stuff...Just proceed slowly and all should be fine
 
For scale i should probably add that i used about 3/4 of a tube on a 10g tank (i Really didn't want those things to move, ever). Its probably too much and the curing is slowed (center of the blobs is harder to get to) and made more intense (silicone/water ratio high) because of it.
 
For scale i should probably add that i used about 3/4 of a tube on a 10g tank (i Really didn't want those things to move, ever). Its probably too much and the curing is slowed (center of the blobs is harder to get to) and made more intense (silicone/water ratio high) because of it.

Bingo, assuming these "universal rocks" you mentioned are some aquarium-purposed product. Otherwise my guess would have been if you had used cement and then not cured it sufficiently and pH went up to approximately ten million on the 14-unit scale :lol:

But 3/4 of a tube in a 10 gallon tank is a ton, and you most likely did have thick areas that were still releasing whatever it releases. Not to mention 12 cichlids in a 10 gallon being a lot as well...
 
Probably cure time. I usually run carbon for a couple days after doing any silicone work.
One thing I noticed in the post though... Foam background. Be aware that most house insulating foam contains HBCD or some other Brominated organic molecules used as a Fire retardant. almost all of these are KNOWN marine pollutants. They kill fish.
Just an FYI for the DIY guys.

Note: Most Dow Great stuff is fine. Just avoid the fire retardant kind.
 
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Bingo, assuming these "universal rocks" you mentioned are some aquarium-purposed product. Otherwise my guess would have been if you had used cement and then not cured it sufficiently and pH went up to approximately ten million on the 14-unit scale :lol:

But 3/4 of a tube in a 10 gallon tank is a ton, and you most likely did have thick areas that were still releasing whatever it releases. Not to mention 12 cichlids in a 10 gallon being a lot as well...

Now you have a few posts crossed. :hmm5: The 10 fish were in a 185 gallon tank with the background made by that Universal Rocks or whatnot. The 3/4 tube was in my 10g with only a few snails, no fish. Which is still alot, sure, but the snails are guinea pigs and i won't put anything but a single one in there until that last single one stays alive. Poor snails fate...
 
Sorry for you loss. It can be devastating. Like the summer 05 storms in MO that cooked and killed my tank while the power was off for 3 days while I was out of town.

However, I do not think you are doing the community a service with the title of the thread.

Our hobby is predicated on building knowledge, and that is based on facts. Not opinions or hastily based conclusions.

The fact is that many others including I have used GE silicone II for many many years without problems!!!
The fact is also that some people have had horrible things happen to their tanks shortly after using GE silicone II.
The conclusion that based on the second fact alone GE silicone II is always toxic is not a fair and valid one.

Everything is toxic under certain circumstances:

Kids drown in 1 inch of water.
The NaCl (salt) in my lab has a toxic warning on it. 50 ppm salt will kill most fish, 35 ppm is blissful.
Sucrose (sugar) ground finely is very flammable.

Silicone II is a neutral cure silicone (it releases ammonia and methanol). Both of these are very toxic to animals. After it has cured pure silicone is viewed non-toxic (safe for drinking water applications). Except PERHAPS the mold inhibiting versions (kitchen and bath) that have some anti-mold agents in the silicone. I haven't seen any solid data these actually cause problems in reef tanks, but it certainly is possible.

Silicone I leaches acetic acid while curing. Acetic acid is much less toxic to fish (we even add it to calcium hydroxide (ball pickling lime) to increase solubility of the calcium.

But both silicones are essential inert after curing.

So why do people use II?
II sticks better to plastics than I, and I sticks better to glass then II

I literally just used GE silicone II clear on saturday evening to reseal a bulkhead. I dropped the level of the tank below the bulkhead, pulled the bulkhead out , cleaned it, resealed, it waited 24 hrs, refilled. Corals were fine before. Corals are fine after.

My larger 140 g tank is completely sealed with Black GE silicone II. I did by let the silicone cure for weeks before I put in fish and corals (siliconed before leaving for vacation). But many other times I've used GE II sealed tanks after 24 hrs or even less (just o.n.) . The fish are fine. The corals are fine.

SO, please don't just blame GE silicone II without reflecting on the situation.

You used GE silicone II. Your fish died. These are facts.
How and/or If GE silicone II lead to fish dying is not necessarily clear.
If you did not wait until the silicone cured (24 hrs, not just the 3 hr setting time), then it could be the Silicone II releasing ammonia and methanol. However, in that case, it is your fault for not following directions. It could be some independent event (pulling fish out and placing them in a holding facility, etc is all very stressful for fish).

I can understand if this experience makes you restrict you use of silicone to the "aquarium safe" labels. But it is just not as clear as Silicone II is toxic and kills fish.

In any case, I hope in the future that you will start a thread with facts rather than conclusions and let the community help you derive at the cause of the mishap (or disaster in this case).

Mike
 
Nematode...if you read my follow up you would see I let it cure for 3 days and did follow directions.

I used 1.5 tubes of Silicone II on 185 gallons of water. No ammonia, nitrate,nitrite ever registered meaning it was cured. Still curing, it would put off ammonia. Corals are also much different than fish. Power outage for 24 hrs, fish die, corals do not.

Kids drown in 1 inch of water??? What is wrong with you. How is that relevant or even socially appropriate to say.

I'm just saying that, "in my opinion", Silicone II is not worth the risk based on my experience and others that I have read. $400 of fish dead because I wanted black silicone that I could buy at Depot/Lowes. Order the Dow 999A or AGA silicone from the pet store or any others that specifically say Aquarium Safe. Wish I would have done that......

End of story...again, just my 2cents and opinion. Take it however you want
 
I am just saying titling the thread.
"Could GE Silicone II have caused my Fish deaths?" would have been more appropriate.

And just to balance the issue I would simply point out my opinion from my experience (and others who have posted here)

using Black Silicone II is not risky and poses no danger either to corals or to Fish.

And I would further to say that it is highly doubtful that your use of black GE silicone II is what killed your fish.
 
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