Yeah, definetly have the backup plan like set up for sure and have a net/pet store cup on hand incase someone gets too violent.Is it just the two of them? I would suggest lots of decor/plants. And either have an extra tank on hand, or some money saved for one. Also keep extra media in your current tank or filter - that way you can transfer the media into a new filter for an instant cycle to a new tank if you need to. Maybe you can just keep an extra sponge in the tank.