Pool Info: Pool Chlorinators
Swimming pool chlorine feeders make introducing a sanitizer into your pool or spas water simple. Fill the chlorine feeder with chlorine tablets or sticks, and select a setting on the dial. Regulate the chemical feeder to the desired setting and allow the chemical reserve to be depleted before refilling. A reliable chemical feeder will limit your maintenance. The type of pool chemical feeder you use depends on the type and size of pool or spa you have. Below is a summary of the major types of chlorinators available for the residential swimming pool market.
Erosion Chlorine Tablet Feeders
The most common type of chlorine feeder is the erosion feeder. Solid, compressed chlorine or bromine, (In a stick or tablet form) are placed into the feeder. Water flows over the chlorine pucks or tabs and dissolves the slow-release tablet. Chlorine or bromine in the form of Hypochlorous acid is then released into the water as the tablet is dissolved. Erosion chlorine feeders are adjustable by a dial, to regulate the amount of sanitizer introduced into the pool water. A perfect feeder would keep a constant dissolve rate, or deliver a constant chlorine flow, regardless if the unit is full or near empty, but in the real world, a full unit may require a lower dial setting, and as it empties, a higher setting may be needed, to maintain a constant flow of chlorine, and prevent peaks and valleys in chlorination.
POOL CHLORINE FLOATERS: A common type of erosion chemical feeders is a free floating chlorine/bromine puck or tablet dispenser called a "floater". Floaters are offered in various forms. Some are larger and hold larger 3" stabilizer tablets or sticks, while smaller spa floaters are made for smaller 1" bromine tablets. All chlorine and bromine dispensers will have an adjustable collar or similar design to allow for the user to control the amount of the chemical being introduced. Floaters will have a series of slits that can be open or closed to determine the volume of water entering and exiting the floating vessel. Proper circulation is needed for a chlorine or bromine floater. If a chlorine floater remains in one spot for an extended period of time it could potentially cause a brown stain on plaster or bleach out a vinyl liner, especially near steps and ladders. Tie them off with a small cord to keep them from free floating. Tipping over is another hazard of pool floaters from heavy winds or cannonball splashes. Always remove a pool or spa floater before getting in the water, and keep the lid tightly secured to prevent spilling tablets in the pool.
AUTOMATIC CHLORINATORS: Another type of erosion feeder is installed at the filter system. In the shape of a cylinder, chlorinators (unlike a floating chlorinator), requires a certain amount of pressure supplied by the circulation system to dissolve the chlorine or bromine tablets or sticks. The flow and amount of chlorine introduced into the water is regulated by a flow control dial, and also by how many tablets (or stix) are in the chlorinator at any given time.
Made by CMP, Hayward, or Pentair, an automatic pool chlorinator is plumbed directly in line on a horizontal pipe after the filter system, and after any pool heater, or can be installed off line. The water is then "pushed" over the chlorine or bromine tablets, dissolving them slowly. The newly chlorinated water is then "pushed" out of the chlorinator, through another hose, and is injected into the return line. The freshly sanitized water is then returned to the pool through the return line.
Off line automatic chlorinators are supplied by a hose that feeds untreated water from after the pump discharge into the chlorinator. Off line chlorinators are more prone to clogging, but may be used if there is no suitable placement for an in line unit, which requires 8-10” of clear pipe at or near ground level, after any filter or heater.
Proper placement of a pool chlorinator is imperative. Pool water with a high concentration of any chemical should not run through suction pipes or any of the pool equipment. All feed lines coming from a chemical vessel with chlorine or bromine should be introduced just before any return valves so the chlorinated water can reach the pool and spa. Off-line hoses can also be installed on vertical return pipes, just before they enter the ground.
Any swimming pool heater is highly subject to the corrosion that can be caused by extreme levels of chlorine. A copper or cupronickel heat exchanger will develop leaks with the presence of merely fumes. Typical heater installation manuals call for an additional check valve to be plumbed in between the heater and any pool chemical feeder, but if you can install a chlorinator at ground level, after the heater, you may not need a check valve, nor expect any damage to the heater.
Maintenance on chlorine feeders, especially floaters is low. Automatic pool chlorinators may need occasional replacement parts, and should be cleaned and lubricated annually. Wear rubber gloves and use clean water and a clean textured sponge to remove gummy, crusty deposits around the chamber and lid. Small bottle brushes can be used to clean standpipe orifices. Apply Teflon lube to chlorinator lid o-rings. Off line chlorinator hoses and injectors should be serviced or replaced every year to prevent clogging and breakage.
It is very important that granulated chlorine is NEVER added to an erosion feeder, and bromine is never added to a feeder used for chlorine. This could cause injury or even death!
Fast dissolving chlorine granules regardless of concentration will build up pressure within a chemical feeder and create a home-made bomb. Avoid an unwanted explosion and potential injury or death by reading instructions and only using the chemical feeder for the intended purpose in conjunction with the correct chemicals, and never use it for any other chemical.
Also important is to use caution when opening a chlorine feeder or bucket of chlorine tablets; strong fumes can escape and burn throat and lung tissue if inhaled. Always empty chlorine tablets and bits, and dry pool chlorinators completely when storing for off season; keep the lid loose to avoid dangerous gas build-up.
Liquid Chlorine Feeders
Probably, the most commonly used type of chlorine in the world is liquid chlorine (Sodium Hypochlorite). This chlorine is primarily used on commercial pools that require a large amount of chlorine to maintain a safe sanitation level. Liquid chlorinators are usually mounted over a 50 gallon vat filled with liquid chlorine, and pumps liquid chlorine into the pool's plumbing.
Sometimes called peristaltic pumps or metered chemical pumps, with an output control dial and a time clock incorporated into these chlorinators, it is easy to regulate the amount of chlorine injected into the water. Digital models are available and more advanced models can be programmed to operate remotely or via controller. Liquid chlorinators are rarely used in the residential swimming pool market.
Pool chemical pumps can also be used to pump chemicals for pH control or any other liquid specialty pool chemical. They operate by means of a suction hose and a discharge hose. The suction hose draws the chemical from a vat, usually 5-50 gallons in size, and then pumps it into the pool return line, via a one way injection fitting. The pump creates the vacuum and pressure with a rotating wheel and a diaphragm or hose.
They are fairly low maintenance systems, but will require occasional replacement of hoses and after a few years, some internal pump parts will need service or replacement. Injectors and hose nuts should be cleaned annually, and pump tubes under the constant pressure of the roller, can split or otherwise fail within 1-2 years.
Liquid feeders have the dangerous potential to leak, in the hose, at the connection to the pump tube, or at the injection fitting. Chemical pumps should always be mounted firmly to a wall or level shelf, above the liquid chemical. They must be in an indoor pump room to protect the feeder and chlorine vats from the elements, and to be out of reach of children or pool users.
Liquid chemical feeders for pools are made by Blue-White, Jandy, Polaris, Rola-Chem, Stenner, among others. They are sized by the maximum feed rate of chemical they can pump, from 1 to 100 GPD (gallons per day) and most units are priced in the $300-$500 range.