The best hard-water study was funded by the softener industry — we say so, then report exactly what it measured: heater efficiency per 5 gpg, tankless deliming intervals, fixture failures, and a 10-year cost-of-doing-nothing scenario with every assumption labelled.
Bottled feels cheap a case at a time; RO feels expensive on one day. Priced per gallon over five years for three households — with every line of math shown, break-even months, and the bottled route that stays competitive.
Your Consumer Confidence Report lists what your utility detected, the legal limit and the health goal — in ten minutes you can read it like a regulator. MCL vs MCLG, the units, lead’s separate rule, violations, and the report’s blind spots, with the lookup tool embedded.
“NSF certified” alone means almost nothing. Each standard — 42, 53, 58, 401 — certifies specific contaminants for a specific model. Here is what each one actually covers, who certifies it, and the three label tricks.
Almost every bag softens identically; purity, form, and price are what differ — pellets at 99.65–99.8 percent verified purity, solar crystals at 99.5–99.6 percent, rock salt as the sludge-heavy exception, and potassium chloride at roughly five times the bag price plus 20–25 percent more product. Annual use is derived from the sizing method and shown for three households, from about $32 to about $184 a year in salt.
Sizing is arithmetic, not bathrooms: convert hardness (mg/L ÷ 17.1), compensate for iron and manganese, work out grains per day, and pick the size that delivers about seven days at 70 percent of its box rating. The calculator is embedded, and every worked example is shown by hand so you can check it.
Pre-filters at 6–12 months, membranes at 2–3 years — but the real schedule, cost and membrane test differ by model. Manufacturer intervals for five systems, floor-counted annual costs from about $44 to $134, and the $15 TDS check that beats any indicator light.
A tank RO system sends about 9 gallons a day to the drain for a family — roughly $33 a year at typical rates. We read the ratios correctly, work the math, and show when tankless efficiency actually pays.
Angi averages about $1,500 installed and HomeGuide bands salt-based systems at $1,200 to $3,800 — but your loop, drain, and outlet decide your quote. Labor vs parts, cost drivers, and three worked totals from $916 to $2,591.
The sticker is the smallest number. Equipment, installation, every filter and media change added up for three representative setups — about $1,380 to $1,999 over five years, with the arithmetic shown.