i have been there ... can see it clearly ...
about  6 -7 feet each . about 10 - 20 .. u can even feed the arapaima with breads . I threw the burger last time ..

Quite true, i guess there is oxygen shortage, my CKF is now gasping for air. zz

as long as ur a fish lover. ur rare fish keeping wont just end here..
trust me.. i am an example for u..

started at:
7yrs old = betta splendens, goldfish, snakehead.
9-12 = discus, gourami keeping
13-15 = massive discus breeding, characin collection (tetra). flowerhorn, marine fishes (basic)
16 = stop fish keeping. start to like cars. dont like ppl call me "gold-fish man"
17-20 = continue fish keeping. yellow tail aro. marine fish (coral tank, damselfish and common clown breeding)
21-22 = back to basic fish keeping. marine fish (angelfish, surgeons and tangs). got a 2005 toyota vios, start modifying like crazy. everyday go sunway area, yamcha, lepak, genting. behave like a "sampah masyarakat"
23-till now = sold my car. not worth modifying. then arowana. RTG, HB, BBXB, BBGH now and going to the max.. planning 8footer at home, no fark..

BenSow,

Actually count your blessings bro. I just realized you are still in high school - when I was your age I didn't even have a handphone what more an aquarium to keep all sorts of exotic fishes. If I were you, I'd consider myself so lucky because compared to other 15 year olds, you're already ahead of the curve. I admire your enthusiasm in wanting to earn your own money to support your hobby and trust me I understand what it feels like to have parents who don't understand your passion; been there done that. Perhaps you should take up ggMing's offer to work part-time but don't let it interfere with your studies. The fishes aren't going anywhere but you as a person - you're going places. 

ggMing,

Looks like I have quite a bit of planning to do and I think the best way going forward is for me to determine a budget and then you can suggest various combinations of fishes that fall within the price range. Obviously I'd need some help with the construction of the pond - how deep it should be, tiled or cement covered sand for the bottom, whether it should have various depths or same depth throughout, how to properly use stones/rocks/driftwood etc to make it as authentic as possible and much more.

Although you said filters weren't necessary, I feel its something I should at least look into as I'd want the water to be as clear as possible. This definitely needs proper planning to coincide not only with the dry season as currently ground too soft and wet to construct anything properly as well as being ready to receive fishes that are ready to leave the grow out tank.

Right now I've got even bigger fish related problems - been trying for the past couple of months to source for Pacific Bottle Nose Dolphins and currently the Solomon Islands seems to be the nearest place but their prices are steep; over RM1m per dolphin and I need five. I don't suppose you could help me with that could you? LOL 

BenSow - bottle nose dolphins are cetaceans and since their original habitat is the open ocean, you can't keep them in your aquarium. Currently we're planning on constructing a 600,000 litre aquarium which does not include the open air dolphin enclosure. This is a very small setup as the consultants we've spoken to have constructed private aquariums up to 1.6mil litres in size but they are usually in the palaces of the Arab royal families. To give you a sense of the size, Aquaria KLCC is about 1.2mil litres and that is a public aquarium. These are all marine based setups however.

But the dolphins I've been looking to source aren't for me neither is the 600,000 litre tank but is actually a tourist attraction project.