GE Silicone I and Fish Logevity?

[Mastiffman]

I heard in the last year that some GE Silicone I versions have started to become unsafe.

 If this unsafe silicone was indeed used on a tank but cured for a good week or two, how long would it take for the fish to be affected?

 I know that uncured silicone can kill fish within hours. But would it take longer for the bio seal or fully cured "mildew resistant" silicone to have an affect on fish to the point of death?

 Thanks.

[jamarini]

The silicone sealants that are intended for bathroom applications have used an arsenic-containing mildewicide for obvious reasons and although I'm not entirely sure about this, it's also likely a similar mildewicide is used in the silicone intended for outdoor use for the same basic reason.  However, most silicone sealants intended for sealing window and door applications do not include a mildewicide.  These are the ones that can be safely used in aquarium sealing. 

To your question regarding how long the leaching of arsenic salts from the cured sealant can have a deleterious effect on fish, like all things it will depend upon several factors but my understanding is that the leaching occurs progressively.  As you can imagine, in the intended applications (like bathrooms) it's advantageous to have mildew protection over a protratcted time period so the sealant doesn't allow mildew and mold to quickly develop on it.  And, the way typical mildewicides are effective is through migrating from the bulk of the sealant to the outer cured surface.  I doubt that anyone has generated data with respect to how long and in what concentrations the arsenic remains in the water and can affect fish.  It likely takes very little amounts of arsenic to kill organisms - that's why it's used to control mildew and mold.

It's best to use only aquarium grade silicone sealants as a rule.  I've never attempted, nor happened to accidently use mildewicide-containing silicone sealant so I hesitate to offer remedial suggestions.  I suppose some things might work but removing the inappropriate types of silicone sealants from a tank and being scrupulous about getting it ALL out and then replacing it with silicone sealant that does not contain arsenic salts to control mold and mildew.  GE Silicone I is safe as are other brands that are clearly intended for aquarium use.  There is a sticky note that details this subject here on the forum but I can't recall offhand just where it is.  If you were to search for safe silicone sealants or something along those lines, I'm confident it will come up. 

I hope this helps.  Good luck.

Jim

[dstuer]

I have had success using GE1 window and door, but as stated above, it doesn't have the mildew suppressor that the bathroom products do. 
It has worked for me where there is "lack" of tensile needed, but where pressure pushes seams apart, or where the frame is compromised it has failed.  In those situations I would  go with one of the RTV products that are more than simply sealants.
I repaired the tank below, sandwiching the cracks with glass panes on the inside and out of the tank with GE1 window & door, it has been up and running about 2 years

[Mastiffman]

Thank you both for the replies! So Im guessing it wouldnt take 2 months to start seeing issues?

Either way I think Im in the clear as I used the same stuff that you have laying down in that picture.

Ive always looked at the labels and did my research long ago when installing a 3D background in my 180g tank and that has been fine. It just kind of made me nervous about a tank that I used the GE I windows and doors 100% silicone on as Ive had issues with some bizzare deaths in it this last year after resealing it but its been confirmed by others that they have had issues eith thr same fish. But thinking back, there has been a duration where there were no losses. So I thinknit was a disease thing and not a tank issue.

I have since nuked the tank with bleach numerous times, then used abondant amounts of seachem safe to dechlorinate it.  in between reseedings and the last issues were most likely from thr fish tht I put together.
 
I just receieved some fish that are literally extremely rare and I wanted to make sure I was doing everything right to avoid any losses.

[mibwb]

I use Loctite silicone the aquarium safe one, says right on the package or Marineland aquarium sealant. I was told years ago, if it doesn't say for aquarium use...don't use it, why chance it.

[Steve]

Any issues from the wrong silicon will show in the first day or two in fish deaths. GE silicon I* is safe, long as that's what you used you are fine, they have not changed that in years no matter what you have heard.

[Mastiffman]

Good to hear. I think it was with the best of intensions but sometimes people hear stuff and it spreads like wildfire before being confirmed legitimate.