Water Filter Pitcher Replacement Comparator
Brita and PUR each publish one filter-life figure that applies to every household. ZeroWater's own replacement chart works differently: it ties the same cartridge's life directly to your tap water's TDS (total dissolved solids) reading, a number neither of the other two brands' own pages ask for at all. We fetched all three brands' own current support pages directly and built the comparison each one's own numbers actually support.
Where ZeroWater's range comes from
ZeroWater's own chart bands TDS into six ranges (0-1, 2-50, 51-200, 201-300, 301-400 and 400+ ppm) and states a gallon range for each one, unmodified here — no interpolation beyond picking the band your entered reading falls into. The 0-1 ppm band states no gallon figure at all; that reading is shown as-is, not converted into an invented number.
What this does not do
- It does not include filter price. Pack prices and promotions change often on each brand's own store pages, and none of this cluster's other comparators assert a price that isn't independently re-checked at build time — this one leaves cost out entirely rather than cite a number likely to already be stale.
- It does not adjust for a brand's own secondary advice to replace early if taste or flow changes — all three brands' pages mention this as a caveat, not a number, so it isn't part of the arithmetic.
- It treats your entered gallons-per-day as constant. Real households vary day to day; a one-off heavy-use day (guests, canning, filling a large jug) will use a filter faster than the flat daily rate here predicts.
- It only covers three brands' own current flagship pitcher filters, not every model each brand sells, and reflects each page as fetched on 2026-08-24 — brands change these figures without much notice.