I used BioKaskades, (small) in my prototype reactor but any good spiked ball or BioPak will do. Avoid DLS or other mat-type materials as these clog and hold detritus much too easily. I would also caution against any scintered glass medias. These have phenomenal surface area but again, are so closed-cell that clogging could be an issue over time.
Once the inner area has been loaded with your choice of media, it is time to attach the top, cut-off end of the coiled tubing to the intake nipple.
