The recirculating biopellet reactor was bound to happen sooner or later, but Reef Dynamics (formerly Euro Reef) is the first one out the gate with a working model for an adjustable, self propelled biopellet reactor. Just like a calcium reactor or recirculating protein skimmer, the design of the recirculating biopellet reactor means that the biopllets can be churned at full bore while only having a modest flow or trickle through the biomedia which is especially helpful if you want to match the outflow from the bioreactor to the intake from a protein skimmer.
Unlike the diminutive biopellet reactors from CPR, Reef Dynamics recirculating biopellet reactors are built for aquariums with 135 gallons up to 1000 gallons and although they don’t quite slip discretely into the sump, their design is particularly well suited to external use. Full pricing and product details on the Reef Dynamics website.