We have a wonderful pond in our backyard that we have really tried to economize on. We recycled materials from a friend who no longer wanted her pond. I really like ponds with koi in them but the cost for one is rather prohibitive. What I did was go to a local pet store and bought "feeder" fish and put them in our pond. These fish were designated to be dinner for other animals but here, they have been given a pardon and are flourishing! Oh yeah, and I paid $1 for 8 a couple years ago.