so the best aquarium size is just mathematics, but the best shape? Now that's a bit more challenging. 

My First two aquariums are shown here, a one-way door let's people in then they must walk all the way through. 

This is actually a screenshot of my first fire, but when I shared it everyone seemed surprised by the aquarium that I just thought was like a normal sensible way to aquarisize. I wanted two big aquariums, but I also wanted long stripes so people can see the fish easily, like an aquarium I maybe used to go to as a kid. 

Obviously this is early and not very complex. Adding decorations, benches for a rest, and a forced exit through the giftshop as per SOP improve things greatly. 

You can make it more elaborate with more tanks. Be aware the heated one needs a heater for each arm and they will need service access. 

What do you think?