Hello Lee . . .
The Ultima II is not a true bead filter since it doesn't use spherical beads as media; in fact, its media is more akin to K1. While it is designed to do both mechanical and biological filtration at the same time, only a beginning hobbyist would use it as a stand alone filtration system.
Most of the folks on the koi boards use it for mechanical filtration before other filtration (such as J-mat, TT, Baki, etc.) or use it after the other filtration to polish the water.
Kindest regards,