Fantastic value - this filter comes complete with a powerful 9w UVC for just £99.99!! This size of box filter is the most popular we sell. At last a genuine multi-chamber professional filter box that anyone can afford. We feel sure that these units will prove a hit. Dirty water enters through the multistage hosetail past the UVC where it is pushed through foam into the first chamber of biomedia. The water then flows into a second chamber and is forced upwards through the foam up and over into the final chamber. Clean water then returns. NOTE: UVC bulb included.