nice ponds. i have plans for a monster indoor pond to build when i get out of school, in about 5+ years. i have lots of possible designs for indoor ponds. all range from about 2000 gallons all the way up to around 100000 gallons. one of my plans is for a pond that is about 20ftX15ftX8ft. in a pond that size i can put almost any type of fish that i could get my hands on. i already have one fish that i will put in an indoor pond when i get one. it is a common pleco named Lizard. he is about 8 and a half inches long right now and growing extremely fast. ive had Lizard for about 10 months, when i got him he was an inaccent little 3 inch baby pleco. now he is the largest fish in my tank. i have him in a 30 gallon tank. I hope he survives for a very long time.