Bio Barrels make a great media for trickle filters and degassing towers.  Available in three different sizes, it is easy to find one that will fit your application.  All media is made from polypropylene for long life and safe use in aquatic environments.  All Bio Barrels are sold in one cubic foot increments.  

Please note that 3.5" Bio-Barrels require a minimum order of 50 cubic feet.