This tank blew me away. It's even better than the big one ADG had setup years ago with a bunch of blue discus, white sand, two islands of Swords on both sides and Halide lights to get the shimmer effect.
It is so apparent that the discus and the cories feel great in this tank. I cannot even imagine how he keeps the tank so clean. But notice one thing - the tank is 1000 liters and his filter is 300 liters. So a filter that is 1/3 the volume of the tank. Also the biomedia is "Siporax" which is a biosubstrate popular in Europe. As I understand it has a huge surface area - more than most biomedias. Either way - keeping this tank in the shape that it is is just about a miracle with discus.
Also note the flow - it is pretty strong. The hairgrass at the bottom is leaning and moving on the current. The cories that venture in the grassy area swim against a current.
Another interesting detail is how both discus and cories prefer to hang around the open area with no plants. The discus do not appear to have stunted growth. This means that water changes must be pretty often (every other day maybe). http://www.youtube.com/watch?v=9CJiKGCryFw