CentsPerGallon
What Every Gallon of Filtered Water Really Costs You, Filters and Membranes Included
Whole-house, reverse osmosis, under-sink, pitcher and shower filters compared on what each gallon costs once the replacement filters and membranes are counted. Every price, rating and certification line comes from the maker's own pages, with the date it was read.
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- Cost per gallon1 article
- ComparisonsComing soon
- Whole house2 articles
- RO, under-sink and pitchersComing soon
- Certifications and basicsComing soon
Price trackers
- Water Filter: Black Friday 2026 price tracker · Daily price ledger
Latest reviews and guides
Cost per gallon
Need a New RO Membrane? Replacement Cost Is $62.99 – Check TDS First
Aquasana's SmartFlow RO membrane is $62.99 and lasts 12 months; its carbon pair costs $183.98 a year. APEC and iSpring sets compared, plus the TDS check.
Whole house
Reverse Osmosis System for Whole Home – Or Kitchen RO From $224.99
Whole-home RO adds a tank, pump and pretreatment. Price it against kitchen RO at $224.99 to $579.99, then EPA's well tests and a 7-step checklist.
Whole house
Whole House Water Filter System: $3,394 Add-Ons for a $1,998 Rhino
Aquasana's three priced whole house add-ons list at $3,394 to $3,494, more than the $1,998 Rhino; pre-filters add $73.98 a year. Plus EPA well tests.


