BF4800 Capacity: 12,000 GPH Features: -Support bars add stability and reinforce top grate.-Media bag and filter mat media provide maximum surface area for development of beneficial bacteria (media sold separately).-Dual filter mats for exceptional biological filtration.-Sturdy bottom grate supports filter media.-2" or 3" Heavy-duty FIPT bulkhead for high flow rates.-Bottom chamber will accept bulkhead on all sides while bottom cones reduce surface area for more efficient back flushing.-Heavy-duty removable top grate allows natural rock camouflage.-26" Waterfall width; max pump flow: 6,000 GPH.-48" Waterfall width; max pump flow: 12,000 GPH.-38" Waterfall width; max pump flow: 8,000 GPH.-19" Waterfall width; max pump flow: 4,000 GPH.