Chlorinator - Pool Chlorine Feeder System Basics Guide

A chlorinator is a pool or spa treatment device that feeds chlorine into the water to maintain sanitizer levels automatically.

Chlorinator diagram — labeled parts, dimensions, and installation context

What It Is

A chlorinator is used in swimming pool and spa systems to dispense chlorine in a more controlled way than adding chemicals by hand every day. It helps maintain enough sanitizer in the water to control algae, bacteria, and cloudy-water problems.

The device may hold chlorine tablets, meter liquid chlorine, or generate chlorine from salt depending on the system design. In all cases, the goal is consistent disinfection without sharp swings in chemical levels.

Types

Tablet chlorinators dissolve chlorine tablets in a small canister or feeder body. Liquid feed systems pump measured sanitizer from a storage tank. Saltwater systems use a generator cell that converts salt in the water into chlorine during circulation.

Where It Is Used

Chlorinators are used on residential pools, spas, and larger shared aquatic systems. They are installed in the pool equipment area near the filter, heater, and circulation plumbing so the sanitizer enters the return line before water goes back to the pool.

How to Identify One

A chlorinator is usually a canister, feeder tube, or control box located on the equipment pad. It may be labeled for chlorine tablets, liquid feed, or salt generation and will be tied into the pool plumbing or electrical controls.

Replacement

Replacement is common when the feeder body cracks, internal valves fail, the lid no longer seals, or the control unit stops dosing reliably. Because chlorinators involve corrosive chemicals and pressurized plumbing, repairs should follow the manufacturer's procedure and local pool code requirements.

Chlorinator — FAQ

What does a chlorinator do in a pool system?

A chlorinator adds sanitizer to the water automatically so chlorine levels stay more consistent. That helps control algae, bacteria, and water quality problems without relying entirely on manual dosing.

Is a chlorinator the same as a saltwater system?

Not exactly. A saltwater generator is one type of chlorinator because it creates chlorine from dissolved salt. Other chlorinators use tablets or liquid chlorine instead.

How do I know if my pool chlorinator is failing?

Signs include low sanitizer levels despite normal settings, leaks at the feeder body, cracked housings, or controls that no longer respond correctly. Pool water can also turn cloudy or develop algae if chlorine feed becomes inconsistent.

Can I replace a chlorinator myself?

Simple feeder swaps are sometimes straightforward, but chlorinators still involve plumbing, chemical handling, and sometimes electrical work. If there is any doubt about compatibility or safe startup, a pool service technician is the better choice.