Increase your Biofall's Filtration Capacity with these. Simple place in the mesh bag that comes with the filter and lay them on top of the filter mats.

Depending on the amount of sediment in your system it is sufficient to wash the Bioball's ( and Biofalls Filter Mats) out one or twice a year.  Always try to use rain or un-chlorinated water so that all of the bacteria is not killed off in the process.