Reverse Osmosis System Cost in San Diego
Reverse osmosis is the standard for high-purity drinking and cooking water. An under-sink RO unit pushes water through a semi-permeable membrane that removes dissolved solids, heavy metals, and trace contaminants down to near-zero. Most San Diego homes run RO at the kitchen sink for drinking water and a separate whole-house conditioner for the rest of the house. Cost is driven by stage count and certification more than by city.
Cost breakdown
Reverse Osmosis System Cost by San Diego region
The same system costs differently across the county. Coastal salt air, backcountry wells, and estate plumbing each move the number. Pick your area to see the local page.
What drives the price
- Stage count: a standard 4 to 5-stage unit versus a premium build with extra polishing stages.
- Remineralization: an alkaline or mineral stage that adds taste and minerals back after the membrane.
- Certification: NSF-certified membranes and housings versus generic components.
- Faucet and tank: a designer air-gap faucet and larger storage tank add cost.
- Install: a simple cold-water tie-in versus adding a line to a refrigerator or pot filler.
- Water source: very high TDS or well water can call for a larger membrane or a whole-house RO, which costs far more.
Common questions
How much does a reverse osmosis system cost in San Diego?
A quality under-sink reverse osmosis system runs from roughly $350 to $800 installed for a standard 4 to 5-stage unit, and $600 to $1,200 for a premium build with a remineralization stage. Filter changes cost about $80 to $200 a year. A whole-house RO, which is rare and reserved for very high-TDS or well water, is a different category entirely at $3,000 to $8,000.
Is reverse osmosis worth it if I already have a whole-house filter?
For drinking and cooking water, yes. A whole-house conditioner handles scale and a whole-house filter handles chloramine, but neither removes dissolved solids and trace contaminants at the molecular level the way an RO membrane does. Most San Diego homeowners pair the two: whole-house treatment for the house, under-sink RO for the water they drink and cook with.
How much does it cost to maintain a reverse osmosis system?
Ongoing cost is modest. Pre-filters and post-filters get changed once or twice a year and run about $80 to $200 annually depending on the unit. The RO membrane itself lasts several years before it needs replacing. That is far cheaper over time than bottled water for a household that drinks filtered water daily.
Reverse Osmosis System Cost by city
Local cost pages for reverse osmosis system across San Diego County.
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