Is this silicone safe for my aquarium?

  • We are currently upgrading MFK. thanks! -neo
As long as it doesn't have a mold inhibiting agent in it, you are fine, though there are far better choices out there for silicone. What are you using it for? Also, almost all silicone is inert after it cure so you shouldn't have any issues if you give it plenty of time after you apply it
 
Is that GE Silicone I or GE Silicone II?

Both are probably safe. I used GE Silicone II from home depot on my tank. I used about 4 tubes of it to get my DIY background secured in place. No issues with it, been holding strong for about 1 year now.
 
Both GE I and II are safe as long as you give them time to cure. Both are completely inert once cured. Are you using it for the baffles or for the actual sump holding the water? If you are building the sump I'd find a better silicone.
 
the GE silicone 1 is fine. I've used it plenty of times for smaller tanks (up to 55). The silicone 2 has mold inhibitors and such in it and should be avoided. I've read that over time chemicals are released into the water. I've never used it, just read it.
 
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