nomoreink

Before I saw online that you can buy silicone sealant for your aquarium I used a hot glue gun to seal the upper plastic portion of my 20 gallon aquarium. I haven't tested it yet to see if it actually completely seals off the leak, but was more worried about whether or not the glue used would be toxic to any fish I might later put in the aquarium. Any ideas?

RiffDawg15

I have heard of some people using hot glue to seal small parts of their tanks. Also some ornaments that might have been chipped or parts broken off, they hot glue back together and then place them back into their tank. So my guess would be that hot glue should be safe to use.

Hopefully someone else with more knowledge can give you a more accurate answer.

nomoreink

I did a bit of searching and it looks like a lot of people, including some professionals, use hot glue for fixtures and decorations, etc in their tanks with no problem, so it looks like hot glue is not toxic to fish. Many do recommend silicone instead because of its flexibility.