Maybe I missed something. My apologies if am wrong, but how are you going to house all your monster fish? The largest tank that you have stocked and using is the 55 gallon and a 240 gallon that isn't ready. Did I miss someting about you having or building a tank the size of a swimming pool.
240 gallon, not set up.
55 gallon, 2 oscars, 4 african cichlids, 1 aro, 1 uro.
30 gallon, 1 pacu, 1 giant gourami, 1 comon pleco.
12 gallon,babytank, 1 parroonshark, 1 ck.
Let me kind of break down what I believe you are saying. 55 gallon: 2 oscars 12" easy, 4 african cichlids up to 4", don't know what kind of aro but smallest grows up to 36"', uro 10".
30 gallons: Pacu (you must be kidding me) 30" and thick, Giant Gourami (qouted by Wikipedia) "Gourami can grow from 75 mm to 500 mm (20") in four years", 1 Common pleco 20".
12 gallon "baby tank": 1
paroon shark (From Wikipedia) "Full-grown adults can reach ten feet in length (300 cm) and weigh up to 646 pounds (300 kg)

". 1 Clown knife 40".
Now you got youself an African Aro and are planning to get more. And on another post you said you just bought a 3/4" Datnoid. Where are you putting it? If you put the 3/4" Dat in any of your tanks you have stocked, it will only be an expensive feeder.

I'm just totally lost on what you are planning to do. Some of these fish will outgrow any of the tanks you have (including your 240 gallon) within a year

.
Please enlighten me so I could do it too, I want to get a giga and I have a huge used betta bowl for it. The Doctor.