As someone who has had/has some outdoor ponds myself (3500g and 8500g) I must say yours is very impressive. Love how it turned out and the effort shows!
get some tsn's, red tails, and an arapaima!!!! lol just kidding, but really your best bet would be to populate some big cats. better investment in the long run! im truly jealous.
you should put some of those spa fish (garra rufa i think) in there. the ones that eat the dead skin cells. get cleaned while you relax and drink a beer. great looking pond! thanks for sharing.