In the last few years, my wife developed an interest in aquaponics - a process of growing food in a closed loop system with fish. We started small with a few, 3 inch long Koi in a 55 gallon tank that supported a small, 6 square foot grow bed. It took a short while to find the right balance, but we managed to reach a nice equilibrium and produce pea shoots, Swiss chard, flowers, and herbs.

Fast forward, 2 years, and those 3 inch Koi have grown to 12 inches and no longer fit in the tank. For a moment, we considered digging a pond in the back yard. In order to ensure the fish would survive New England winters, however, we would have had to dig the pond to a depth that would require us to treat the project like an in-ground pool – complete with permitting and a safety fence around it.

So, instead, we decided to do what any crazy set of engineers would do, and build a 250 gallon tank in our house! Of course, we turned to SOLIDWORKS to detail out the design and give us our first sense of scale, proportion, and a materials list.

We cut and assembled most of the structure in the garage, but moved it into the house before it got too heavy.

Final assembly and painting happened in situ.

We used a standard pond liner to hold the water and, although I was a bit apprehensive about it leaking hundreds of gallons of water all over our house, I am happy to say that it is performing beautifully. A small submersible pump runs continuously and pumps water and 'fish nutrients' to a gutter in which the peas grow.

The Koi seem quite happy with the additional space. We even purchased 2 more to add to the family!

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The finished product...