Ozone oxidation + filtration
How a Whole-Home Ozone System works
Generates ozone on site to oxidize iron, manganese and sulfur and to disinfect — then filters the solids out. Installed whole-home, most often on wells.
A whole-home ozone system generates ozone gas on site, injects it into your incoming water, and holds it in a contact tank. Ozone is a strong oxidant: it converts dissolved iron, manganese and hydrogen sulfide into solid particles and inactivates bacteria. A filter downstream then removes those solids. It is used mainly on private wells (EPA — Private Drinking Water Wells).
Typical cost: $2,500–$6,000 installed
How it works
An ozone generator makes ozone (O₃) on site from air or concentrated oxygen. Nothing is stored or delivered — it is produced on demand and used immediately.
An injector mixes the ozone into your incoming water, which then holds in a contact tank. That dwell time is what lets ozone oxidize dissolved iron, manganese and hydrogen sulfide into solid particles, and inactivate bacteria.
Oxidation alone does not remove anything — it just changes the form. A filter after the contact tank is what physically takes the newly-formed solids out, which is why post-filtration is part of the system rather than an add-on (EPA private wells).
The components inside
What each part does, in the order water moves through the system.
- 1Ozone generatorProduces ozone on site from air or oxygen, on demand.
- 2Injector / venturiDraws the ozone into the water stream and mixes it.
- 3Contact tankHolds the water long enough for oxidation and disinfection to finish.
- 4Vent + ozone destructSafely releases undissolved gas and converts it back to oxygen.
- 5Post-filterRemoves the iron, manganese and sulfur solids that oxidation created.
Configurations & options
One whole-home ozone system is not like another. These are the real choices that change cost, maintenance, and how well it fits your home — worth understanding before you get quotes.
- Ozone vs. air-injection (AIO) vs. chlorine feed
- All three oxidize iron and sulfur so a filter can catch them. Air-injection is the simplest and cheapest and handles moderate levels with no chemicals. Chlorine feed handles heavy iron and iron bacteria and leaves a residual, but adds chemical handling and can leave taste. Ozone is the strongest oxidant of the three and disinfects as it works, with no chemical to store or taste — at a higher price and with more equipment to maintain.
- Air-fed vs. oxygen-fed generator
- Air-fed units are cheaper and adequate for typical residential loads. Oxygen-fed (concentrator) units produce more ozone per hour and run more consistently in humid conditions, which matters when iron or sulfur levels are high. Feed gas needs to be dry either way — moisture cuts output and shortens generator life.
- Ozone alone is not a full treatment train
- Ozone does not soften water. On a well that is both hard and high in iron, the usual order is ozone plus its filter first, then a softener running on cleaner water. If the goal is lowering dissolved solids or arsenic, ozone is not the answer — reverse osmosis or adsorptive media is.
What it addresses
- Dissolved iron that causes orange and rust staining
- Manganese (black staining)
- Hydrogen sulfide — the rotten-egg odor
- Bacteria, including iron bacteria, as water passes through
Learn about these contaminants
Common questions
- How does a whole-home ozone system work?
- A generator makes ozone from air or oxygen. An injector mixes it into the incoming water, which then sits in a contact tank long enough for the ozone to work. Ozone oxidizes dissolved iron, manganese and hydrogen sulfide into solids and inactivates bacteria. A filter after the tank removes the particles that oxidation created.
- What does an ozone system remove?
- With filtration after it, ozone addresses dissolved iron and manganese staining, hydrogen sulfide (rotten-egg odor), and bacteria including iron bacteria. It does not soften water, does not lower total dissolved solids, and is not a primary arsenic treatment — those need a softener, reverse osmosis, or adsorptive media.
- Does ozone leave anything in the water?
- No. Ozone breaks back down to oxygen within minutes, so there is no chemical taste and no residual left in your plumbing. That cuts both ways: unlike chlorine, it leaves no lasting disinfectant downstream, so the system treats water on the way in rather than protecting the pipes after it.
- How much does a whole-home ozone system cost?
- Typical installed range is $2,500–$6,000, because the system is really three parts: generator, contact tank, and post-filtration. Your real price depends on your well-water test — iron, manganese, sulfur and bacteria levels all change the sizing. Get an estimate rather than a fixed sticker number.
- Is an ozone system certified?
- Not the way a softener or UV system is. There is no NSF/ANSI performance standard that certifies residential ozone drinking-water units — NSF/ANSI 50 covers pools and spas, NSF/ANSI 46 covers wastewater, and the ozone-generator document (NSF/ANSI 222) explicitly does not evaluate treatment effectiveness. Ask instead that wetted components meet NSF/ANSI 61 and that any post-filter carries its own certification.
Pros & cons
Pros
- Strongest of the common oxidizers — handles iron, manganese and sulfur together
- Disinfects as it oxidizes, without adding a chemical
- No chemical to store, and no residual taste in the water
Cons
- No residual disinfectant downstream, unlike chlorine
- More equipment than an air-injection filter: generator, contact tank, vent and post-filter
- Ozone gas is a respiratory irritant, so venting and an ozone destruct unit are not optional
- No NSF/ANSI performance standard certifies residential ozone drinking-water units
- Does nothing for hardness, dissolved solids, or arsenic
Best for
Whole-home treatment where iron, manganese or sulfur come with a bacteria concern — most often private wells, and city-water homes wanting oxidation for taste and odor.
Sizing basics
- Sized from a well-water test: iron, manganese, hydrogen sulfide, bacteria and flow rate.
- Ozone output is matched to the contaminant load — undersizing leaves iron in the water.
- Contact tank volume sets the dwell time, and peak household flow sets the tank size.
- The post-filter is sized to the solids the ozone will create, not to the raw water alone.
Solves these water problems
Next steps
Know the tech and the options — now get a real price for your water, or find a vetted local pro to size and install it.
Sources
Explore other system types
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