Making A Cave

[MrGT500]

i have a piece of lava rock in my tank has 3 holes in the center of it, i was useing a piece of slate on the top of it to turn it into a cave, but the slate keeps falling off. what kind of appoxy is safe to use to glue the 2 rocks together?

 

[SchottayB]

Aquarium Silicone

 

[tomtomtom1230]

Some super glues are OK, not sure what chemical you have to look for though. To be safe, I'd use aquarium silicone.