Indoor pond build

[Dgmannn412]

I want to build an indoor amazon basin.
I have a monster garage built on the wrong side of the dam house so I'm going to fill it with my small zoo. I want to build a pond roughly 12X6X4 if my math is rite it's roughly 2100 gallons. I'm thinking steel skeleton wrapped in cement sprayed with sealant. I have a pump that pushes 100gallons a minute and 4 55gallon barrels set up as a filter.
Now my post if for this reason who has a pond that isn't filled with koi and didn't hire a pro to do it for you. I want to know the best idea for constructing a pond of this size. What are good options for materials sealants frame skin liners. What should the plumbing in the floor lay out like. Should I try gravity fed or just muscle it out with the pump. Is a skimmer useful in doors. Would a water fall or a gentle flow return be better. Should I run 1 return or 2. Is a 6000 gallons an hour enough to filter 2100. I plan on keeping big predatory fish. I already have Oscars arowana shovel nose catfish bichirs Dempseys and more. I don't want to miss something and can't afford to do it twice. I'm tiered of the idea my fish won't get to full size in an aquarium so I want something big enough to do the job. I figure 72 square foot should be enough space.

 

[duanes]

I have used Intex (and other brands) swimming pools for this purpose, for keeping cichlids indoors and outdoors.
As an inexpensive, and easily removed alternative to something permanent (which could lower the value of the building if you ever decide to sell.
I usually placed a standard pond filter (for mechanical) and sent the flow thru a biofractionation unit (protein skimmer)..
I would recommend air exchange units to prevent humidity damage to the building.

 

[TheKingOfDaFishes]

I have also used intex metal frame pools. I just used two diy waterfall filters with pumps, garbage cans, pond mats, and charcoal. I would go higher on the gph for best quality water especially with big predatory fish. I've never used skimmers although I could probably use one.

 

[Dgmannn412]

Thank you for the intex idea. I will keep it in mind. I've come to conclude that 2100 gallons is small considering my ultimate goal. I'm thinking now that I want to go closer to 4k or even 5. The now 4 pump system should do roughly 2400gpm. With restrictions plumbing and whatnot I'm assuming it will be more like 1800gpm. I am still stuck with the concept of construction should I go rebarb for cost or square steel framing. I'm going to pour concrete over it and use 1 1/2 inch lexan for viewing. I figure no matter how big the pond 2x3ft. Windows should be fine at 1 1/2. I'm also wondering if 50gal sediment chamber followed by 50gallon media chamber full of media blocks will be enough. I usually filter my aquariums 10plus times per hour with the smallest filter being 30 cubic inches of biomedia. On a 55 gallon. I'm figuring 21 times an hour it will filter over 30 cubic feet of media stone. Am i in the rite ball park or am I completely out on left field. Is this something anyone knows or is it going to be a do it and hope it's good enough. Everything hepls Thank you in advance