That is a sweet mini pond!!
If in a couple of years when your Red Arowanas mature I hope some of yours pair up. Toss some floating water plants in there and if your lucky you maybe have got a shot at Red Arowanas breeding.
There was a guy (I forgot where exactly) out of South East Asia somewhere that bred his Arowanas in a pond that was very similar to yours. He had some floating water hyacyths though. You may already know whom I'm referring to, when it happened it was big news.