Automatic Pool Chlorinators: Buyer’s Guide

Chlorine tablet in water with bubblesChlorine Tablets are the easiest and safest way to get chlorine into your pool.

Automatic Chlorinators are the perfect partner, allowing a way to provide a constant and consistent chlorine level.

Using tablets in the skimmer? That’s a No-No, and can cause big problems over time.

Chlorine Floaters? Well OK, better than nothing, but less effective than a real, stand-alone chlorinator, aka chlorine tablet feeder.



Hayward CL200 (In-Line) and CL220 (Off-Line) Feeders

Hayward Automatic Chlorinators are probably the most well known and ubiquitous of chlorine feeders on the market today.

Hayward Chlorinators are available for inground and above ground pools, in both In-Line and Off-Line versions. They feature a venturi standpipe to draw-in chlorinated water, which is cleanable, should it ever become clogged with residue.

9 lb capacity (inground models) is larger than most residential feeders.



Pentair Rainbow Model 320 In-Line and Model 300 Off-Line

Rainbow Automatic Chlorine Feeders are also available in a variety of sizes, to hold 5lbs of stacked tablets, up to 40lbs for the largest model HC3330.

Rainbow feeders offer a simpler lid assembly, with fewer lid o-ring problems as a likely result. Small 4inch lid is easy to open, without a special wrench.

Rainbow Off-Line hoses are noticeably heavy duty, and the base plate is thicker than other feeders, and hold up to twisting force while removing a sticky lid.



CMP PowerClean Ultra In-Line and Ultra Off-Line

Custom Molded Products is a new player on the feeder scene. Their PowerClean Chlorinator brings some interesting features.

CMP Feeders have a clear, see-thru lid to check tablet level, and a side-mounted flow meter. Double Unions allow the In-Line feeder to be easily disconnected for service, storage or cleaning.

Internally, the operation of the PowerClean Ultra borrows design technology from the Hayward chlorinator, while the PowerClean Econ is a Rainbow design.



Sani-King Perform-Max Inground and Aboveground Chlorine Feeder

Not a new player on the scene, King Technology has been patenting chlorine feeders since the early 70’s.

Sani-King Perform-Max chlorine feeders offer the patented Inline Dispersal valve, which only wets the bottom few inches of chlorine tablets, instead of flooding the entire chamber.

Frog Chlorine feeders and New Water Cyclers also use the King Control Dial Assembly, and all have the oversized dials and lids for easier removal.


In-Line or Off-Line Chlorinator?

In-Line chlorinators are plumbed in place, into the return pipe – after all other equipment. Plumb the chlorine feeder into a section of clear pipe, near the ground, so chlorine gas won’t back up into a heater or filter valve. You’ll need a hacksaw, measuring tape and PVC primer and glue.

Off-Line chlorinators are used when there is no room to install an In-Line chlorinator, or not enough clear space on the return pipe, after all other equipment. 2 holes are drilled into the PVC pipe, one before the filter and one after the filter. Hoses are saddle clamped to the pipe to carry water in and out of the ‘Off-line’ or ‘Off the Pipe’ chlorine feeder. rainbow-320-feeder

In-Line is a better way to go, for a more sturdy installation and less parts to replace. If pipe space is tight on the return line the Rainbow 320 In-Line requires only 4″ of pipe to install.

If you do install an Off-Line feeder, be sure to install the base into the concrete or into a heavy block of wood, to keep it steady while opening the lid.

For other questions about how to install or maintain a pool chlorinator, leave a comment below, or reach us by phone or email!

Davy Merino
InTheSwim Blog Editor



Automatic Pool Chlorinators: Buyer’s Guide — 4 Comments

  1. I have to replace my Hayward chlorinator every other year because the top freezes and leaks like a sieve – despite using a lubricant. Do all of these products have that problem, if no which ones are the best?

  2. Hi there,
    Do you know if all inline chlorinators need a check valve on the line? Are there any that don’t? For the offline version is a check valve needed on the main line do you know? Many thanks Nigel Heeler.

    • Hi Nigel;

      A check valve is a one-way flow valve, to prevent chlorinated water from draining out of the In-Line chlorinator and slowly making its way back upstream (when the pump is off), and entering the heater, filter or other equipment. It is not always needed, and need not be, as long as the chlorinator is at ground level, and the other equipment in/out ports for heater or filter are 2 feet higher, off the ground. Use a check valve if your chlorinator is installed at the same level as the heater exit, mounted off the ground, or for heat pumps or cartridge filters, which often have in/out ports at ground level. All manufacturers may recommend a check valve, but it’s not really needed in any cases, as long as there is 1-2 ft. of vertical pipe between the chlorinator and other equipment, and the chlorinator is placed ‘last on the line’, after any other equipment, right before the return side valve (if any), and before the pipe turns down to go into the ground.

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