I have a (noob) question:
Why isn't the pond mentioned in his signature enough for an (nearly 1 ft) Arapaima?
MY POND 16'3'3'[8"Pacu 8"1Tiger Oscar7"5RubyRed Oscar6"2Tiger Oscar1' Albino Catfish 4 Fire Mouth 4 4"Red Devil 6" Black Catfish 4" LG Fh 2"4 RR Oscar 3" Salvani 1' Albino Catfish
If the tank-mates are a problem, I think some of them can be given away as they are not really as "exotic" as an Arapaima.
At OP (Prankur):
I have a 25 ft diameter and 30-40 ft deep (old-style) well in my farmhouse (at Alibag). The minimum water volume (in the Summer) is close to 6000 gallons. (It has some plants growing in it and a lot of moss/algae for biological filtration.)
It is not part of any local water-body (so none of the inhabitants will harm local ecosystems). It is already housing a couple of 1ft albino walking catfish (Clarias batrachus) and a huge common pleco.
The care-takers feed the fish fresh seafood and the catfish seem to be thriving.
So, while I am sure you will run into a million wells like this between Bhopal and Bombay all of them might not have "caretakers". Just throwing this out there as an option (for the non-exotic fish in your pond)
Cheers,
Sid
(The name of the shop is Aakar. I have PMed you the shop details I found online. I plan to go there later today. I will confirm if the details I sent you are current.)