Continuing with the custom tank build, the next step is the tank itself. Here is a picture of the tank from one end. You can see inside one overflow, and see the other on the opposite side. Remember, this tank will be viewable from the two larger sides, and the ends with the overflows will be next to the walls.
This will be one of the viewable sides of the tank. You will also note six holes in the bottom of the tank. These will be used for a "closed loop". 
A closed loop is used to add circulation to a tank, without having to place powerheads (and the visible cords) in the tank. In this case, we will be using a pump that moves about 15 times the tank volume per hour. The pump will draw water from the two larger holes in the middle, to divide the suction in half, so there is less chance of a fish or invertebrate getting stuck to the suction screen. The other four holes are the returns. Each hole will be connected to a motorized valve, that will alternate through pairs of outlets, and create more random flow than you would get from the pump just running all the time through one outlet.More to come.
Jason
