allowing one tank to top off before the next receives water

just cut the tubing feeding water into your unit and insert this in-line softening filter

Electrode: Replaceable glass sensor and reference tube electrodes

The option above adds Catalytic Carbon cartridge in place of 5 micron carbon block

Softner Pre-Filter Cartridge FastFlush allowing one tank to topSoftner Pre Filter Cartridge Softner Pre Filter Cartridge Standard FeaturesOur Softner Pre Filter Vertical Cartridge is the biggest and the best available for this size filter housing. Dimensions and Weight Dimension: 9 7 8" x 2 1 2" Weight: 1 pound Illustrations Diagrams Instructions How to Change Filters