10 Best Inline Chlorinators 2025 in the United States

The Hayward CL200 In-line Automatic Chemical Feeder is a solid choice for maintaining your pool’s chlorine levels. Its ability to use both large and small slow-dissolving tablets provides flexibility in managing chlorine output. The dial control valve is a standout feature, making it easy to adjust the feed rate according to your pool’s needs, which is especially useful for varying pool sizes and fluctuating chlorine demands.

The Easy-Lok threaded cover ensures adding tablets is straightforward and safe, while the unique finger-release catch adds an extra layer of security, preventing accidental spills or access by children. Constructed from durable ABS material and featuring a high-quality Viton seal, the feeder promises longevity and resistance to pool chemicals, which helps in preventing corrosion.

However, it is essential to note that while the feeder is robust, the installation process might require a bit of plumbing knowledge, which could be a drawback for some users. Additionally, it is relatively lightweight at 0.25 pounds, which is good for handling but might raise concerns about its stability once installed. The product is designed to be used with tablets, which might not be suitable for users who prefer liquid or granular chlorine. The Hayward CL200 offers good adjustability, durability, and ease of maintenance, making it a suitable option for most residential pool owners looking for a reliable inline chlorinator.

The Hayward CL220 Off-line Automatic Chemical Feeder is a solid choice for pool owners looking for a reliable chlorinator. It accommodates both large and small slow-dissolving chlorine tablets, making it versatile in managing chlorine levels. The dial control valve is a standout feature, allowing easy adjustment of the chlorine feed rate to suit your pool’s needs.

Installation and maintenance are simplified with the Easy-Lok threaded cover and unique finger-release catch, which ensure both convenience and safety when adding tablets. The unit is constructed from durable ABS plastic and features a high-quality Viton seal, suggesting it will have a long service life.

However, because it is an off-line model, it requires separate plumbing, which might present an additional challenge during installation compared to in-line models that integrate directly with your pool’s filtration system. The CL220 is designed to maintain clean and sanitized water, prevent corrosion, and ensure proper water balance. With a weight of only 4 ounces and compact dimensions, it is easy to handle and install. This chlorinator is best suited for those who need a reliable and adjustable chlorine feeder and are comfortable with a bit more involved installation process.

The Pentair R171096 Rainbow 320 is an automatic in-line chlorinator designed for both pools and spas. It stands out for its capability to maintain consistent water sanitation, which ensures a clean and healthy swimming environment. This model is compatible with both large and small bromine or trichlor tablets, making it versatile for different pool or spa sizes. It can hold up to 11 large or 98 small tablets, which offers convenience for less frequent refilling.

The installation is relatively straightforward as it integrates permanently into the return line of new or existing systems and comes with 2” slip PVC fittings and adapters for 1-1/2” lines. However, it's worth noting that unions are not included, which might be an additional purchase for some users. Durability and material quality seem reliable given its good reviews and the fact it is made in the USA.

One possible drawback could be the lack of included unions, which might complicate installation for some users. Additionally, while the feeder is designed for permanent installation, this might limit flexibility for those who prefer temporary setups. This chlorinator is ideal for users looking for a dependable and efficient solution that offers good adjustability and ease of maintenance.