When selecting a chemical feeder for pools, the key considerations are reliability, ease of use, and capacity. The Pentair Rainbow HC-3330 stands out as the best overall due to its durability and precise dosing. For those seeking affordability, the U.S. Pool Supply In-Line Feeder offers reliable performance at a lower price. The Hayward CL200EF is a strong choice for in-ground pools that require consistent chemical delivery. However, buyers face tradeoffs between capacity, ease of maintenance, and compatibility with different pool types. Continue reading for a detailed comparison to find the best fit for your needs.
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Key Takeaways
- The top picks balance capacity, ease of installation, and chemical compatibility, with no one-size-fits-all solution.
- Reliability and build quality are key differentiators, especially for long-term pool maintenance.
- Capacity matters: larger feeders reduce refill frequency but often come with increased size and cost.
- Ease of use and maintenance can significantly impact long-term satisfaction, especially for DIY pool owners.
- Price varies widely; selecting a feeder that matches your pool size and chemical needs prevents overspending or underperformance.
| Pentair Rainbow HC-3330 Chlorine/Bromine Chemical Feeder | ![]() | Best Overall for Safety and Monitoring | Series Compatibility: 300 and 320 | Color: Clear amber | Maximum Operating Pressure: 50 PSI | VIEW ON AMAZON | See Our Full Breakdown |
| Hayward CL200EF In-Line Automatic Chlorine Feeder for In-Ground Pools | ![]() | Best for In-Ground Pools with High Capacity Needs | Capacity: 9 lbs | Installation: In-line offline | Compatibility: In-ground pools | VIEW ON AMAZON | See Our Full Breakdown |
| U.S. Pool Supply In-Line Pool Automatic Chlorine Feeder – 9 lb Capacity | ![]() | Best for Above-Ground Pools with Ease of Monitoring | Chemical Capacity: 9 pounds | Material: ABS Plastic | Compatibility: Hayward CL200 Chlorinator | VIEW ON AMAZON | See Our Full Breakdown |
| Hayward CL220EF Off-Line Chemical Feeder, 9 lbs Capacity | ![]() | Best for Safe, Off-Line Chlorination | Capacity: 9 lbs | Type: Off-Line Chemical Feeder | Material: PVC | VIEW ON AMAZON | See Our Full Breakdown |
| HydroTools by Swimline 8750 Super Premium In-Line Automatic Chlorine Feeder | ![]() | Best for Fun and Flexibility with In-Line Setup | Capacity: 9.0 lbs | Chlorine Tablet Size: 3 inches | Compatibility: Above ground & Inground pools | VIEW ON AMAZON | See Our Full Breakdown |
| Pentair Rainbow 320 Automatic In-Line Chlorine/Bromine Feeder for Pool and Spa | ![]() | Best for Permanent In-Line Installation in Pools and Spas | Brand: Pentair | Model Number: R171096 | UPC: 788379004385 | VIEW ON AMAZON | See Our Full Breakdown |
| chemical feeder for pool | Capacity | Compatibility | Material |
|---|---|---|---|
| Pentair Rainbow HC-3330 Chlori | — | — | — |
| Hayward CL200EF In-Line Automa | 9 lbs | In-ground pools | Corrosion-resistant housing |
| U.S. Pool Supply In-Line Pool | — | Hayward CL200 Chlorinator | ABS Plastic |
| Hayward CL220EF Off-Line Chemi | 9 lbs | — | PVC |
| HydroTools by Swimline 8750 Su | 9.0 lbs | Above ground & Inground pools | — |
| Pentair Rainbow 320 Automatic | Holds 11 large or 98 small bromine or trichlor tablets | — | — |
More Details on Our Top Picks
Pentair Rainbow HC-3330 Chlorine/Bromine Chemical Feeder
The Pentair Rainbow HC-3330 stands out for its fully enclosed design, which minimizes gas escape—a key safety feature compared to open or semi-open models like the HydroTools 8750. Its clear amber enclosure allows for easy tablet level monitoring, simplifying maintenance. However, with a maximum operating pressure of 50 PSI, it may not suit high-pressure systems, and its compatibility is limited to specific filter series like 300 and 320. This feeder is ideal for owners prioritizing safety and straightforward visibility, especially in systems where gas management is a concern. Its enclosed system and NSF listing make it a reliable choice, but those with higher pressure pools or incompatible filters should consider alternatives.
Pros:- Easy tablet level monitoring with clear amber design
- Fully enclosed system prevents gas escape
- NSF listed for safety and quality
Cons:- Limited to 50 PSI maximum pressure
- Specific compatibility may restrict use with other filter systems
Best for: Pool owners seeking a safe, easy-to-monitor chemical feeder compatible with specific filter series
Not ideal for: Owners with high-pressure systems or incompatible filter setups requiring broader compatibility
- Series Compatibility:300 and 320
- Color:Clear amber
- Maximum Operating Pressure:50 PSI
- Enclosure:Fully enclosed system
- NSF Listed:Yes
Our verdict“This feeder suits safety-conscious owners who prioritize visibility and compatibility with select filters, but may not be ideal for high-pressure or incompatible setups.”
Hayward CL200EF In-Line Automatic Chlorine Feeder for In-Ground Pools
The Hayward CL200EF excels in automatic chlorine delivery for in-ground pools, offering a high 9-pound capacity that outperforms smaller feeders like the U.S. Pool Supply 9 lb. Its in-line offline design ensures consistent dosing, but it requires proper installation and manual fine-tuning, which could be a hassle for DIY owners. Compared to in-line models like the HydroTools 8750, it provides more capacity and durability, making it suitable for larger or heavily used pools. This feeder makes sense for pool owners prioritizing automation and capacity, but those with simpler setups or smaller pools might find it overkill and more demanding to install correctly.
Pros:- Automatic chlorine distribution maintains water chemistry
- High 9 lbs capacity reduces refilling frequency
- Corrosion-resistant construction for durability
Cons:- Requires proper installation and setup
- Limited to in-line offline configurations
- Manual adjustments needed for precise control
Best for: In-ground pool owners needing a reliable, high-capacity, automated chlorinator
Not ideal for: Owners with above-ground pools or those seeking a simple, plug-and-play solution
- Capacity:9 lbs
- Installation:In-line offline
- Compatibility:In-ground pools
- Material:Corrosion-resistant housing
Our verdict“This pick is ideal for larger in-ground pools where automation and capacity are priorities, but installation complexity may deter casual users.”
U.S. Pool Supply In-Line Pool Automatic Chlorine Feeder – 9 lb Capacity
The U.S. Pool Supply 9 lb is tailored for above-ground pools, emphasizing ease of installation with a transparent lid for chemical level checks. Compared to the Hayward CL200EF, it’s more straightforward for smaller setups, but it doesn’t include tablets or sticks, requiring owners to purchase those separately. Its durable ABS construction resists corrosion, yet manual refilling can be a hassle for owners with large or heavily used pools. This feeder makes sense for budget-conscious owners wanting simple operation, but those with larger pools or seeking an all-in-one kit should explore more comprehensive options.
Pros:- Easy to install and operate
- Durable, oxidation-resistant ABS plastic
- Transparent lid for quick chemical level checks
Cons:- Tablets and sticks not included
- Requires manual refilling
- Limited capacity for large or heavily used pools
Best for: Above-ground pool owners seeking a simple, easy-to-monitor feeder
Not ideal for: Owners with large or in-ground pools needing higher capacity or automated features
- Chemical Capacity:9 pounds
- Material:ABS Plastic
- Compatibility:Hayward CL200 Chlorinator
- Application:Above Ground Pools
Our verdict“Ideal for above-ground pools needing straightforward, easy-to-monitor chemical addition, but not suited for larger or heavily chlorinated pools.”
Hayward CL220EF Off-Line Chemical Feeder, 9 lbs Capacity
The Hayward CL220EF offers a safe, enclosed design with no venting needed—making it a strong choice over open designs like the HydroTools 8750. Its 9-pound capacity fits most pool sizes, but being an off-line model, it limits flexibility and requires separate plumbing. The enclosed PVC construction prevents fumes from escaping, which is a significant safety advantage, although the capacity might be insufficient for very large pools. This feeder is well suited for owners who prioritize safety and compatibility with PVC systems but want to avoid the complexity of inline setups.
Pros:- Enclosed design prevents fumes from escaping
- Easy access with threaded cover
- Compatible with most PVC systems
Cons:- Limited to off-line installation
- Capacity may be insufficient for very large pools
Best for: Pool owners needing a safe, enclosed, off-line chlorination solution compatible with PVC plumbing
Not ideal for: Large pools or those wanting inline automation with higher capacity
- Capacity:9 lbs
- Type:Off-Line Chemical Feeder
- Material:PVC
- Venting:No venting required
Our verdict“This feeder suits owners who prioritize safety and compatibility over high capacity or inline automation.”
HydroTools by Swimline 8750 Super Premium In-Line Automatic Chlorine Feeder
The HydroTools 8750 combines a playful glow-in-the-dark, solar-powered design with in-line automatic chlorination, making it appealing for above-ground and inground pools that owners want to monitor visually at night. Its capacity for five 3-inch tablets is modest compared to larger feeders like the Hayward CL200EF, and it relies on sunlight for optimal operation. This model is less suited for large or heavily used pools due to its limited capacity, but it offers an engaging, customizable experience for owners who enjoy a bit of fun with their pool maintenance. Compared to the more utilitarian Hayward CL220EF, it emphasizes aesthetic appeal and night visibility, at the cost of capacity and ease of use in low sunlight conditions.
Pros:- Solar-powered with glow-in-the-dark feature for night visibility
- Adjustable chlorine output for customized control
- Visual tilt indicator simplifies refilling
Cons:- Tablets not included, requiring separate purchase
- Limited to 5 tablets at a time
- Sunlight dependency may affect performance
Best for: Owners of small to medium pools seeking a playful, solar-powered chlorinator with night visibility
Not ideal for: Large pools or owners needing high capacity and consistent automation under all conditions
- Capacity:9.0 lbs
- Chlorine Tablet Size:3 inches
- Compatibility:Above ground & Inground pools
- Power Source:Solar-powered
Our verdict“This feeder is perfect for fun-loving owners with small to medium pools wanting a solar-powered, visually engaging chlorination option, but less suitable for large or heavily used pools.”
Pentair Rainbow 320 Automatic In-Line Chlorine/Bromine Feeder for Pool and Spa
The Pentair Rainbow 320 stands out for its straightforward, permanent in-line installation, making it ideal for users who want a hands-off approach to chemical dosing. Compared with the Hayward CL200EF, which offers a similar capacity but is designed more for in-line use with a focus on durability, the Rainbow 320 is easier to set up in existing return lines thanks to its standard fittings and compatibility with a variety of bromine and chlorine tablets. However, it’s limited to in-line placement and does not include unions, which could add to installation effort. This feeder’s capacity to hold up to 11 large or 98 small tablets makes it suitable for larger pools or spas, but the lack of included unions might be a drawback for DIYers. Overall, this model is a reliable choice for those seeking a permanent, low-maintenance solution for chemical feeding in pools or spas.
Pros:- Easy to install permanently in existing return lines
- Compatible with a wide range of bromine and chlorine tablets
- Includes standard fittings for flexible setup
- Suitable for both pools and spas
Cons:- Does not include unions, potentially increasing installation costs
- Limited to in-line installation only, reducing versatility
- Requires permanent plumbing modifications
Best for: Pool and spa owners who want a durable, permanently installed feeder with broad tablet compatibility.
Not ideal for: Homeowners looking for a portable or off-line chemical feeder, as this model requires permanent installation in the return line.
- Brand:Pentair
- Model Number:R171096
- UPC:788379004385
- Item Type:Pool and Spa Chlorine/Bromine Feeder
- Capacity:Holds 11 large or 98 small bromine or trichlor tablets
- Installation:Permanent in return line
- Fittings:Standard 2″ slip PVC with adapters for 1-1/2″ unions
- Warranty:1 year
Our verdict“This feeder is best suited for pool owners seeking a reliable, permanent in-line solution with straightforward installation.”

How We Picked
I evaluated each chemical feeder based on performance, build quality, capacity, ease of installation, and maintenance requirements. Reliability in chemical dosing and compatibility with common pool chemicals were crucial factors. Price was also considered to ensure value for different budgets. Products were ranked to highlight those offering the best balance of durability, usability, and capacity for typical pool sizes and setups. This approach ensures the recommendations cater to both casual pool owners and those with more demanding needs.| chemical feeder for pool | Compatibility | Material |
|---|---|---|
| Pentair Rainbow HC-3330 Chlori | — | — |
| Hayward CL200EF In-Line Automa | In-ground pools | Corrosion-resistant housing |
| U.S. Pool Supply In-Line Pool | Hayward CL200 Chlorinator | ABS Plastic |
| Hayward CL220EF Off-Line Chemi | — | PVC |
| HydroTools by Swimline 8750 Su | Above ground & Inground pools | — |
| Pentair Rainbow 320 Automatic | — | — |








