Dishwashers and kettles, as we all know hard water is a real pain to all our appliances including washing machines.
Some water softeners use a brine solution and resin beads which collect the hard water salts. While cleaning the resin beads and allowing them to regenerate and collect the hard water salts again softening the water, These must be regenerated which is where an automatic backwash system comes in. Not to mention all the other bits you can not see just like your plumbing, drainage and heating/storage tanks.
The other side of things is a PH correctioner which if you have a low PH level under PH 7 after that, you have acidic water which can cause absolute chaos with humans, metals and anything which we need the water to come into contact with. It can stop a pump in quarter of the time it will take the pump to last normally.
PH correction units are specified on the basis of water test results and the media inside of them comes into contact with the acidic water and creates a small natural chemical reaction which boosts the PH to a neutral 7 -The media continues to dissolve into the water until the PH level is achieved. You will most commonly see it on copper or metal pipes which have turned a light green colour.