Swimming Pool Blog
by Rob Cox, May 11, 2010
Saltwater Chlorinator Systems
Saltwater Chlorine Generators, also called Salt Systems or Salt Chlorinators are fairly simple to understand. You pour salt (NaOCl2) - into the pool, about 200lbs per 10000 gals of pool water and this salty water is pumped through a salt cell, or electrically charged metal plates. Fancy folk call the process an oxidation-reduction reaction. I call it chemistry! The salt breaks down into it's components and mixes with the H2O, or dissassociates, as expressed by the following equation.
2 NaCl + 4 H2O = 2 NaOH + 2H2 + 2HClO
This translates to be that when electrically charged titanium plates are immersed in salt water, the salt + water will convert to chlorine, water and a little by-product called sodium hydroxide. The same salt is converted, reverted and re-converted into chlorine again and again. It's a miniature chlorine factory. You just add salt to the pool and turn it on.
Many people have concerns about adding so much salt to the pool. But it is nowhere near the salinity level of the ocean. At normal levels, a salt water pool is about 15 times less salty than the ocean. So, it won't taste salty, won't sting the eyes, but does give the water a slightly silkier feel.
Of course, you still have to pay attention to water balance - pH, Total Alkalinity and Calcium Hardness levels. Keeping a proper level of chlorine stabilizer (cyanuric acid) is also a good idea to reduce demand on your salt cell. Start-up and periodic salt additions to the water to maintain the salt level per manufacturer is necessary.
Having a salt water chlorine generator won't make your life that much easier, but it does provide these key benefits:
- Keeps chlorine level fairly constant
- Allows you to shock the pool at the push of a button
- Reduces production of Chloramines, which smell bad and turn eyes red
- No more handling of hazardous chlorine chemicals
- No more storage of hazardous chlorine chemicals
- No more transporting of hazardous chlorine chemicals.
But perhaps the best reason to use a Saltwater Generator is that it's good for the environment. Using only naturally mined salt, making your own pool chlorine reduces the demand for industrial production of chlorine tablets and granular products. If you don't know - the manufacture of these oxidizers consumes a lot of energy and produces a lot of hazardous waste. Not to mention the stacks of chlorine buckets that you probably have in your shed, and the transportation by truck and rail of these products to various distribution points, then to the stores, and then driven home by (or shipped again to) the pool owner.
Salt Chlorine Systems are not new. They have been around now for nearly 20 years. In the last several years however, the depth of choice for pool owners had increased sharply and the prices have dropped drastically. Salt systems are now available for aboveground pools in an affordable price range. Once a cottage industry, brought up by Aqua-Rite, Clormatic and Goldline - now all of the major manufacturers now have a salt chlorine generator available. Hayward, Jandy, Pentair and Polaris have all released saltwater chlorine generator models in the last few years.
Installing a saltwater chlorine generator is an easy affair. You have a control unit to mount on the wall, near an outlet so you can always have it plugged in. Then you cut the return line, after the filter, and plumb in the electrode. The Jandy AquaPure Ei salt system, shown on top of the page makes the plumbing part really easy. You just drill a small hole in the pipe (core bit included) and clamp the electrode onto the pipe. Most units now have a straight through method of plumbing in the electrode, avoiding the loop arrangement shown above.
After the box is hung and the electrode, or "cell" is plumbed in, you add some pool salt, at a rate of about 200lbs per 10,000 gals of pool water. Most manufacturers suggest salt levels of 2500-3200 ppm. Your salt system controller will tell you when the salt level is too low, too high, and just right. You can also use salt level test strips to test your pool salt level. A small amount of salt will need to be added periodically to replace backwash water, splash out or winterizing procedures.
Pool salt is sold in 40lb bags for just under $10 per bag. Shipping can be expensive, so best to check out a Home Store or local home water treatment company like Culligan if you are buying large quantities.