I remember seeing the thread for that pond Justin its amazing man
Yep if your wanting aros and you've got the climate and space for a pond I'd definitely go with that option (me and Justin dont get that option as were both in the freezing cold UK ) I would suggest putting a tight fine net over the pond though as arowana do jump and disasters do happen even with a tight lid
A pond like that would be fine a raised one with a viewing window would be much better to look at aros theres not much to see from above , but you'd need a net to cover it or they'll jump out , the pond Justin posted has large glass panels around it to prevent them from jumping
How big is your pond dimensions ? Any pics of your pond ?
You could use a tank as a growout no problem you'll prob need to move them after 12 months depending on the fish size you buy in the first place
Pond looks big enough for aro like I said earlier you'll need a net to cover it , I wouldn't have any rocks or decoration in the pond because it could injure itself on them , plus your koi will get eaten eventually unless they get big quick