The Running Cost Nobody Quotes: Salt, Cartridges, and Water Lost to Regeneration

The installation price is only the first line of a water treatment quote. Over the life of the equipment, the running costs of salt, replacement cartridges, membranes, and the water a system uses to flush itself often add up to more than homeowners expect. Compare these as carefully as the purchase or install cost.

Softener running costs

A softener uses salt each time it regenerates and uses water to flush. Both depend on how much water your household uses, how hard the supply is, and how the control is set. Ask for the salt dose setting and how the system calculates it. Ask whether the control regenerates on demand, based on use, or on a fixed schedule, since a fixed schedule can spend salt and water even in quiet stretches.

Filter and reverse osmosis running costs

Filter systems consume cartridges on a labelled schedule. Reverse osmosis systems add pre-filters and a membrane, each with its own replacement interval. Ask for the full parts list with the interval for every item, and ask the company to confirm whether the parts are proprietary. If you can only buy a part from the installer, the price you are offered today is not the price you will pay later, so ask whether it is fixed for the length of any agreement.

Water sent to drain

Reverse osmosis systems discard part of the feed water to flush the membrane. The ratio of waste water to treated water matters for your water bill and for the total water the system uses in a year. Ask for the manufacturer's stated ratio and whether it changes with pressure or with the condition of your supply.

How to compare two offers fairly

Ask each company for the same figures: estimated salt or cartridge use, the replacement schedule in writing, and the water used in each flush cycle. Put those figures side by side over the same period of years. A lower install price with higher consumable costs is not a bargain if you pay the difference every year.

Questions that reveal the rest

Ask whether you may buy supplies from another source and still keep the coverage the company promised. Ask who orders the parts and who sends the reminders, so the cartridge or the salt does not run out between visits. Ask what happens to your running costs if your household size or water use changes after the install.