Silicone is yellowing

Adam Baggett · Nov 30, 2014

Hello all,

I have a quick question. I needed to move my fish tank and I took the opportunity to fix some silicone on one corner. All looked good but it has started to turn yellow, I also re-did my DIY sump and only part of that is going yellow not all of it. I used DAP All-Purpose Adhesive Sealant 100% Silicone as I could not find the GE II 100% Silicone anywhere. Do you all think this will be OK or do I need to hunt down the GE brand and scrape this out and start again.

There is salt water in the tank now and it is starting its cycle so I am not sure if that is causing the yellow.

DFW · Nov 30, 2014

That says aquarium safe, so should be good, except for yellow color. Weird! And if you use any GE silicone, use silicone 1, not silicone 2! The silicone 2 has mildewcides, and you don not want it!

Adam Baggett · Nov 30, 2014

Thank you. It is weird I am afraid to move my fish in thought when it is ready.

Fin · Nov 30, 2014

Boy, that's anew one on me. Never saw sealant turn yellow like that before. But, I have never used that particular one before. And DFW is right, NEVER use GE Silicone II.