Another thing we are experimenting with at UC is using a cheato ball instead of a typical refugium sections. In the first section of the filter where the water inputs from the display tank you would want to baffle the water to minimize air bubbles from entering. Then using a small powerhead and a spray bar, create a looping current that will slowly tumble the cheato. Tumbling the algae will keep it clean, exposure more of it to the light and result in a cleaner first sump chamber. The second section would feature the skimmer, fluidized media reactor(s) and heater and finally the last section the return pump.