Something I'm tossing around building with a friend. It holds 94,000 gallons, 60 ft. diameter x 5 ft. depth with 20 ft. diameter structure for viewing area in middle. The two square sections over the outer part are bridges to cross into the viewing area. This structure design in the center is being tossed around and may be completely different. Maybe an octagon shape with a viewing window on each face.
your filtration plans would be the big problem but you'd have TONS of space in something like that...
