Vortex chambers are good for settling out heavy waste but much less efficient with the lightweight particles. Have you noticed that even though you get a lot of waste in the bottom of your vortex, you still find that the subsequent chambers get very dirty too. This is the very fine particles that do not have time to settle in the vortex and so they get drawn through the transfer port into the next chamber.

How do they work?

Black Knight brushes work in three ways. First, they physically trap the large particles that cannot pass through the close weave of the interlocking filaments. Secondly, the filaments have a static charge that ‘grabs’ any small particles that are flowing by. This charge holds onto the waste until you do your routine cleaning. Thirdly, after you have been using the brushed for a few weeks, the massive surface area of the brushes becomes home to millions of beneficial nitrifying bacteria that will help to purify your water biologically.