I am in the design process on a similar project. I work for a poured wall company and we specialize in high end custom projects so I am hoping to utilize the discount
. I have been working out some prelim designs for the tank and the filter system. I personally am leaning toward a wet dry on a grand scale. I have made all my filters in the past and have had excellent success. My thoughts were to use a plastic holding tank below grade (very well insulated) for the sump so it would take up less space. There is a plexiglass company in New England that specializes in large aquariums, I might be able to track down a number for you. They gave me ideas and specs on thicknesses for the window. I would defenitely agree you should get the project engineered, I have seen water under pressure do BAD things to concrete.
I would love an update on what you find out.
