So I have a pond outside and I check on it everyday it is quickly losing water and im just about tired of this think. Only fish in there is a monster Xl Comet goldfish and a bluegill. I have a growout tank with a channel catfish a gold koi and a pair of i.d. sharks.In my finished growout tank is a 7" hoplo catfish and a 11"gar that needs a new tank or pond ASAP. The main point of this thread is I need ideas. I definently have plans in the future to have a monster tank/pond but I feel wrong going to the store and just picking out monsters I would rather raise them. I want to make a temporary build something that can sustain water that is adleast 5'L x 3'-4'W x adleast 2'H I want it indoors. It doesnt need a viewing glass just ability to hold water and cheap. As you know in the U.S. our economy is not so good right now I am limited on money but have tons of time to work on this. If anyone has any ideas please let me know I already have filtration,heaters, and ect. Thanks Guys!