I've actually noticed something in your tank other than your outstanding fish,the spray bar you have on the tank bottom,never seen them done that way before.
The way I've set up the spray bars give me awesome circulation. All the crap that falls to the bottom gets pushed into the intake. This leaves the bottom of my tank nice and clean of debris. Heres a thread I made awhile back about it. http://www.monsterfishkeepers.com/forums/showthread.php?t=155862