Well, I'm starting the design of a new tank that will be built when I build my new house out on our farm. It will be a 1000 gallon hexagonal tank with a pillar reef in the center. I like my 3 sided 300 gallon tank but want to go round. I don't like the optical distortion or the cleaning issues with a cylindrical tank. So I will use acrylic and build it to have 8 sides. About 30" deep. I like the fact that with a tank this size and round, I will never worry about tangs again. Will use a combination of controllable sunlight tubes and LEDs to light the reef. The rest will be amplifications of systems I have used for years. Hope to live long enough to get it done.