A system that was sized honestly has a first year that looks like groceries and oil changes, not a remodel. Salt and sediment cartridges are the usual year-1 spend. Resin, catalytic carbon, and iron media are not annual products unless something is wrong.
We will not invent how many bags of salt a Phoenix house uses, how many dollars a dealer service plan should cost, or a rebate. Those numbers depend on hardness, indoor gallons, salt setting, and the contract in front of you.
Salt (self-regenerating softeners only)
Cation exchange consumes sodium chloride or potassium chloride when the valve regenerates. Use goes up when hardness is high, indoor gallons are high, or the salt setting is high. Demand-initiated (metered) valves waste less salt than a clock that regenerates whether you were home or not. EPA WaterSense tells specifiers to look at NSF/ANSI 44 efficiency ratings for water and salt.
Year-1 job: keep the brine tank between the manufacturer’s min and max, use the grade of salt the valve maker allows (and do not fill past the point bridging starts), and watch for a sudden jump in use — that is a leak, a bad setting, or a valve stuck in regen. Portable-exchange customers buy a service visit, not bags.
If the sanitation district forbids on-site brine, year-1 salt at the house should be zero. If someone is still filling a brine tank in SCV, read the LACSD page.
Sediment prefilter cartridges
A cheap spun-poly or pleated cartridge in front of carbon, RO, or an iron filter exists to die so the expensive bed does not. Change it when the pressure drop says so, or at the interval printed on that cartridge’s sheet — whichever comes first. A well that throws sand will eat cartridges. That is information about the well, not a reason to skip the housing.
We will not print “every 90 days” as a universal fact.
Carbon (whole-house or POU)
Carbon exhausts. Taste and odor returning is the 42-style clue. For a PFAS-listed cartridge, EPA’s instruction is stricter: follow the manufacturer’s schedule even if the water still tastes fine, because taste is not a PFAS instrument. Whole-house GAC replacement is a media dump measured in cubic feet and contact time, not a year-1 ritual. Ask the installer what measurement (gallons, chlorine residual after the tank, or a dated calendar they invented) they are using.
Acid-neutralizer calcite
Calcite is meant to disappear. Look in the tank. If the bed is low, refill with the same media the manufacturer specified. That can happen in year 1 on aggressive water. It is not a failure. Retest pH after refills.
Iron / sulfur media (air injection, Katalox Light, greensand family)
These beds are backwashed, not swapped like a refrigerator filter. Manufacturer literature for Katalox Light describes a multi-year media life in some reprints of the technical sheet; treat the current Watch Water sheet as the authority and treat early replacement as a symptom (wrong pH, no air draw, insufficient backwash, iron bacteria). Year 1 is: confirm the air pocket or oxidizer feed, confirm backwash, retest iron and odor.
Softener resin
Resin is not a year-1 consumable on city water that is simply hard. Chlorine, iron, and fouling shorten it. If a contract sells you “resin replacement at month 12,” ask what failed. NSF/ANSI 44 is about the appliance’s tested capacity, not an annual media club.
Reverse osmosis
EPA’s PFAS-filter pages note that RO requires changing pre/post cartridges and, on a longer cycle, the membrane. Use the model’s literature. Sanitize the tank when the manufacturer says to. Wastewater to the drain is operating cost in gallons, not a bag of salt.
A year-1 checklist that does not invent numbers
- Bypass works. You can isolate every tank.
- Hardness after a softener is where you set it (often near zero on a hot-water loop you actually want soft).
- pH after a neutralizer is in a workable range.
- Iron and odor after an AIO are down on a lab retest, not a vial.
- Drain lines still go where the permit and the district allow.
- You have written model numbers and filter part numbers.
If the first-year invoice is mostly “service plan” and you cannot name the media, you bought a relationship. Get the spec sheet anyway.