We love this idea. Hey, fish and water are very restful, and who couldn't use more of that. You can purchase indoor ponds, liners, filters and pumps that are easy to install and safe to use. Indoor ponds are elevated a couple of feet, but you can cover the perimeter with plants and create an indoor grotto for those days when a little water therapy is just the thing to calm your frazzled nerves. There's another advantage, too. If your dining room is under two feet of water, no one will volunteer you to host the next family reunion.