Quote Originally Posted by Morph View Post
if you are using it as a terrestrial set up then just stick a load of silicone over the cracks.
Indeed. Another solution is to just silicone another piece of glass to the cracked one. I'd use it for terrestrial setups only.

Aquarium silicone is the better choice. The ordinary types usually contain antifungal chemicals that may or may not be harmful to animals.