CB1 - So the solids in the tank tend to collect and accumulate under the diffuser?
The
settlable solids do, while the suspended solids (solids that won't or haven't settled) get siphoned to the clarifier tank via the u-tube siphon and trapped in the filter material.
The diffusers pushes air up obviously, which causes water to rise right above the diffuser but to drop farther out and make it's way back to the center drain. Also the the inflow of the returning water to the fish tank from the biofilter (covered in the next post) is directed tangentially to the fish tank wall, which causes a spinning motion in the fish tank that also directs solids to the center drain. For those that don't know it's known as centripetal flow or the "tea cup effect."
