GE Silicone I isn't safe to use in aquarium according to the company

[Emma1234]

Hi everyone,

I was adding baffles to my sump and had read on the internet that GE Silicone 1 is safe to use in aquariums. But before I used it I emailed GE to find out for sure. Below is the response I received. Their response was that it isn't safe for aquarium use due to mold inhibitors. See email below.

I used Weldon for acrylic, but I'm not sure if that is safe.



From: Commercial.Services@Momentive.com [mailto:Commercial.Services@Momentive.com]
Sent: Wednesday, October 18, 2017 8:42 AM

Subject: Inquiry Reply HA9B22517A

Hello Larry,

Thank you for inquiry. Below is our response to your inquiry and your initial inquiry for your reference.

Inquiry Response:

We do not have a product that will work in an aquarium. All of our products contains mold/mildew inhibitors that will kill aquatic life.


Initial Inquiry:
Ask GESA Inquiry
EMAIL SUBJECT: GE Silicone I safe for use in my sump aquarium
BODY: **** EXTERNAL EMAIL - Exercise caution, this email originated from outside of the company. DO NOT reply to, open attachments or click links if the email looks suspicious or is from an unknown sender. ****

Hi,

Can you tell me whether or not GE Silicone 1 is safe to use in my aquarium? I am using it to silicon some baffles in my sump.

Thanks!

[mcgyvr]

GE I has been used by hundreds/thousands of people in their tanks without issue..

That is likely their "generic/broad" statement covering their entire product portfolio.

However whats important is that you let the product fully cure (dry) prior to water/aquatic life contact.. Chemicals are released during curing that could cause problems..
A generic statement there would be to let it cure for 7 days or more..
Best to make a "test bead" as thick as your thickest portion that you can slice into and verify cure,etc...


and before it comes up.. GE II is also usually fine (get type I though) BUT... It has a longer cure time than type I and also is a neutral cure silicone which means it basically releases ammonia during curing.. That ammonia as you know is toxic in our tanks.. The fact that people didn't cure it enough and its that its a neutral cure vs acetoxy cure silicone is what likely caused issues with some who have reported it and thus how type II has gotten the "not reef safe at all" rap that it has on the internet.. Type II is also naturally just more mold resistant.

[davocean]

Pretty much agree w/ all that^^

Only thing I will add though, is while I have used GE 1 many times over the years, it usually discolors and looks cruddy fast, now days I prefer to use aqueon which your petco will carry(RTV would be better) because it bonds better and stays clear, and for the work I put into building a sump it's nice to have something that stays looking clean.

[nereefpat]

Obviously they won't recommend their product to be used for aquariums. Too much liability.

As mcgyvr said, people use GE1, and it's safe as long as it's cured.

[billdogg]

Originally Posted by mcgyvr

GE I has been used by hundreds/thousands of people in their tanks without issue..

That is likely their "generic/broad" statement covering their entire product portfolio.

However whats important is that you let the product fully cure (dry) prior to water/aquatic life contact.. Chemicals are released during curing that could cause problems..
A generic statement there would be to let it cure for 7 days or more..
Best to make a "test bead" as thick as your thickest portion that you can slice into and verify cure,etc...


and before it comes up.. GE II is also usually fine (get type I though) BUT... It has a longer cure time than type I and also is a neutral cure silicone which means it basically releases ammonia during curing.. That ammonia as you know is toxic in our tanks.. The fact that people didn't cure it enough and its that its a neutral cure vs acetoxy cure silicone is what likely caused issues with some who have reported it and thus how type II has gotten the "not reef safe at all" rap that it has on the internet.. Type II is also naturally just more mold resistant.

^^^This^^^

I have used both extensively over the last 30 years. I prefer Type I windows and doors. I would not suggest it's use for tank construction, but for glass baffles in a glass tank it is perfectly fine to use. If you use a thick enough bead, it will also work for acrylic baffles in a glass tank because typically there is little to no pressure differential between the two sides of a given baffle. Acrylic doesn't bond well (at all) with silicone so for acrylic baffles in a acrylic tank, one of the weldon's is the correct choice (4 or 16)

hth

[Emma1234]

OK. Sounds good. Thanks