Fulaik 9500 One in Use One Backup Alternating Regeneration Boiler Softened Water Treatment Equipment Fully Automatic Softener: A single valve controls two resin tanks (one in use and one backup, alternating regeneration) simultaneously, which can continuously supply softened water. Due to the use of soft water regeneration, the regeneration effect is good and suitable for various water consumption conditions. For systems with large water consumption, multiple units can be operated in parallel.