YOU ARE HERE: LAT HomeCollections


Ozone System for Pool a Good Alternative to Chlorine


Question: We spend a lot on chemicals for our swimming pool. Also, the chlorine irritates my eyes and makes my skin dry. I have heard of no-chemical ozone pool and spa purifiers. How do they work and are they safe?

Answer: Ozone is probably the best swimming pool-spa water purification method available, and it is safe. Thousands of municipalities across the country purify their drinking water with ozone. Ozone in water is not an irritant like the ozone in air caused by high automobile pollution levels.

Ozone, often called activated oxygen, is one of the strongest oxidizing and sanitizing agents known. Both effects are needed for swimming pools. The oxidation keeps the water clear and free of dangerous, irritating chemicals and particles. Sanitizing kills bacteria and viruses that can make you ill.

Another benefit of ozone is that it is a natural flocculator. This causes microscopic particles in the pool or spa water to clump together. This makes them big enough so the filter can remove them.

You will still need some residual chlorine level in your pool water. This level is typically only about 10% to 20% as much as a chlorine-only pool. The chemical usage is even further reduced because the oxidation of the harmful chloramines and other chemicals frees up useful chlorine.

Ozone purification systems are simple devices that you can easily install. Ozone gas is created inside a small unit and a tube feeds it into the return water. The circulating filter water, flowing through a venturi, sucks in the ozone just like a carburetor draws in gasoline.

There are two basic ozone generator designs used for pools and spas: ultraviolet (UV) and corona discharge (CD). UV systems use one or two special fluorescent tubes inside an ozone chamber. Powerful UV rays break the air molecules down into ozone just as the sun does in the upper atmosphere.

Corona discharge units create ozone the way lightning does in a thunder storm. Ozone is the fresh smell outdoors after a thunderstorm. These units basically produce tiny lightning bolts inside of the ozone chamber.

Although both designs are effective, UV is the simplest system. If the long-life tube ever burns out, just replace it. Neither design uses much electricity, but the CD systems are slightly more efficient to operate and they produce higher ozone concentrations for large pools.

Instead of using chlorine chemicals for the residual level, consider a new salt system to generate its own chlorine. These salt systems are used extensively in Australia and other countries. They cost little to operate and also soften the pool water so it is very comfortable to swim in.

Write for (or instantly download Update Bulletin No. 917, a buyer's guide to nine UV and CD ozone and salt-type pool-spa purification systems, output levels, features, prices and installation instructions. Please include $3 and a business-size self-addressed stamped envelope and mail to James Dulley, Los Angeles Times, 6906 Royalgreen Drive, Cincinnati, OH 45244.

Clean Damper to Seal Chimney for Summer

Q: Now that the cold weather is over and I will not be using my fireplace, what is the best method to seal off the chimney. Does the built-in chimney damper not seal very well?

A: A chimney is a huge energy waster, especially when there is no fire. In the summer, the sun shines on the chimney and warms it. This causes a natural upward draft to draw air-conditioned air out of your house.

First clean all the soot and ash from around the damper. When clean, it may actually seal better than you think. If it still does not seal, use an inflatable insulating chimney pillow such as the one manufactured by Enviro/Energy Tech.


James Dulley has written a new 224-page book, "Affordable Efficient Houses," which includes 235 floor plan layouts and exterior diagrams and 195 house manufacturers. Included in the nine chapters: timber-framed, geodesic dome, modular, circular, log, steel-framed, paneled, post and beam and cedar houses. You can order this book for $14.95 (includes delivery) with check payable to James Dulley. Mail to James Dulley, Houses, P.O. Box 54987, Cincinnati, OH 45254 or visit

Los Angeles Times Articles