The 9100 SXT digital twin tank valve connects two water softener resin tanks and automatically alternates between tanks as needed. The Digital Metered control measures water use and switches tanks to regenerate as needed to ensure continuous soft water 24/7 with no down time when the unit cycles. The twin tank design provides ultra-high efficiency The user friendly controls have an LED readout with touch pad controls. This fully adjustable 5-cycle control valve delivers upflow backwash, downflow brining, slow rinse, rapid rinse, timed brine refill and downflow service. The system is perfect for light commercial/heavy residential systems that require twin tank conditioning capabilities, or for the consumer that wants the ultimate in water treatment for their home. Continuous flow rate of 21 GPM. All cycles are easily adjustable. The backwash capacity handles water softener tanks up to 16″ in diameter. The 9100 valve uses 100% capacity of the tank in service before switching to the second tank to save both salt and water when compared to standard single resin tank models. The system may be set to regenerate at night similar to most single tank units, but typically is set to regenerate immediately when the tank in use is exhausted to provide an unlimited supply of continuous soft water. The Fleck 9100 regenerates itself with soft water for maximum resin efficiency and to keep the system components clean for optimum operating efficiency and minimum maintenance. The Fleck 9100 is the ultimate in soft water systems.