all the sumps ive seen went
filter wool
coarse spounge
small bio
big bio
i now have
filter wool, coarse spounge, small ceramic noodels, bio balls, and large glass noodles. i was thnking
filter wool then coarse spounge. then on to the drip tray then onto small noodels, coarse spounge, big noodels, course spounge, and then on to the bio balls then going through the drip tray and then under the wall past the heaters then into the pump and back to the tank