slow leak

[Hapkido-ist]

Is there any reason why tanks develop slow leaks? We've had our for a while now and it's just developed a slow leak. What should we do?

ps. it's plastic

 

[ste2k3]

could have had a knock or something and have a tiny crack. I would get a new tank and simply transfer all the stock across, or you could put all the fish in buckets and tyr and seal it with some silicone or if its is ABS plastic, you could weld it with some solvent weld pipe glue.