A chlorinator for a well feeds chlorine into the water continuously so bacteria are killed and iron, manganese and sulfur are oxidized before the water reaches the house. It is the standard answer to a well that keeps failing a coliform test or that smells of sulfur, and it is a system of parts rather than a single appliance.
Why continuous, and not just shocking the well
Shock chlorination disinfects what is in the casing and plumbing on the day you do it. If the source itself is delivering bacteria, or a surface connection is letting them in, the results come back positive again within weeks. Private wells sit outside the federal Safe Drinking Water Act, so no utility is going to catch that pattern for you. A chlorinator is the answer when repeat testing shows the contamination returns rather than being a one time event, and repairing the well cap or grout has not fixed it.
Pellet droppers versus liquid metering pumps
A pellet chlorinator sits at the well head and drops calcium hypochlorite tablets down the casing on a timer or on pump cycles. It is simple and cheap and it disinfects the well itself, but the dose varies and the tablets can build residue in the casing. A liquid metering pump draws sodium hypochlorite solution from a tank and injects it into the line after the pump, proportionally to flow. It costs more and needs a solution tank, and it is the choice when consistent dosing matters, which is most of the time.
Contact time is the part people skip
Chlorine needs time in contact with the water to inactivate organisms and to finish oxidizing iron and sulfide. That is what the retention tank is for, and it is sized against peak household demand rather than average use. Injecting chlorine directly into a short run of pipe ahead of the house gives you the taste of chlorine with only a fraction of the disinfection. If a pressure tank is being counted as contact volume, check what its actual drawdown is rather than its label size.
What has to come after the chlorinator
Chlorinated well water arrives at the house carrying oxidized iron and manganese particles plus free chlorine, so a backwashing carbon or catalytic media filter belongs downstream to strip both. That filter is what keeps the chlorine taste out of the kitchen and protects a softener from resin fouling, since oxidized iron is exactly what ruins a resin bed. Our well water filtration guide covers laying this train out in the right order for a house that also needs softening.
Maintenance you are signing up for
Solution tanks get refilled, pump heads and injection check valves wear out, and hypochlorite solution loses strength as it sits, particularly if the tank is warm or in daylight. Expect to verify residual chlorine at the raw side and confirm no residual is reaching the taps. Retest for coliform after the system has been running, and again seasonally, because a chlorinator that has quietly stopped dosing looks exactly like a chlorinator that is working until someone tests.
Questions people ask about chlorinator for well
Is a chlorinator better than a UV system for a well?
They solve overlapping problems differently. Ultraviolet inactivates organisms and removes nothing, while chlorine also oxidizes iron, manganese and sulfur odor and leaves a residual in the plumbing. Wells with iron or sulfur usually favor chlorination.
Will I taste the chlorine in my drinking water?
Not if a carbon filter follows the contact tank, which is standard practice. Tasting chlorine at the kitchen tap usually means the carbon media is exhausted or the dose has been set higher than the system needs.
Does a chlorinator remove iron from well water?
It converts dissolved iron into particles, which is half the job. The particles still have to be caught by a backwashing filter downstream, otherwise they end up staining sinks and laundry.
How often do I refill the solution tank?
It depends on household water use and the dose the well needs, so treat the first few weeks as calibration and log the level. Sodium hypochlorite also weakens with age, so buying more than you use in a couple of months is false economy.