Alternatives to Chlorine Mean Green Thinking
Dec 11, 2007 07:49PM
Whoever spread the notionÂ that summertime is a blissfulÂ stretch of lazy days surely didn’t have children. That person probably also didn’t have a swimming pool. Those of us with kids and a pool know that summer is the time to be proactive, not lazy.
A pool is a terrific way to keep the kids entertained, providing hours and hours of fun to be remembered for a lifetime. We parents want that to be a long and healthy lifetime, so keeping the pool in good condition is key. While you don’t want a pool that’s green in color, you ought to look at maintaining your pool with green living principles—good for our health and good for the environment.
Two steps are required to properly maintain a swimming pool and make pool water safe from bacteria and algae. These two steps are creating circulation and providing sanitation.
A typical swimming pool has seven components. â€¢ Pool shell â€¢ Pump â€¢ Filter â€¢ Chemical dispenser â€¢ Drains â€¢ Returns â€¢ Plumbing connecting all of these elements
With a typical maintenance system, the water is treated as it is pumped in a continual cycle, from the pool through the filter and chemical treatment systems, and back to the pool again.
Chlorine system Chlorine is the most commonly used disinfecting agent for killing germs and keeping the water clear and blue. Chlorine reacts with water to form hypochlorous acid, which kills bacteria and other pathogens by destroying the enzymes and structures inside their cells.
Although the chlorine method is the most widely used, there is growing doubt whether chlorine is the best means to a healthy family. The question is not whether it keeps the water sanitized, but to what degree the chlorine may be harming the swimmers. Chlorine hovers above the water, and in the long term has been found to cause respiratory problems. Studies show asthma rates are high in swimmers who spend hours in a chlorine pool. In general, children may be even more vulnerable than adults because of the smaller diameter of their airways.
Along with respiratory concerns, chlorine also causes itchy irritated skin, and at times unfortunate episodes of green hair as well as faded swimwear.
Pool system choices More pool owners today look at alternative methods to keep water clean. Ozone, salt, bromine and ultra violet light are methods which can replace or reduce chlorine use. Here is a look at each of these alternatives.
Ozone Ozone gas is essentially oxygen. The oxygen gas found in the air we breathe consists of two atoms together; this is molecular oxygen. Ozone consists of three oxygen atoms bonded together into an ozone molecule.
The ozone pool system includes a generator that pumps the ozone gas into the pool through a small tube. When the ozone gas dissolves in water it comes in contact with impurities, and oxidizes or connects with them as chlorine chemicals do. After ozone is introduced, particles of organics in the water will clump so the filter can remove them more effectively. By treating water with ozone, the breakdown rate of natural organic matter is increased.
The ozone system does not totally eliminate the need for chemicals. A very low residual level of chlorine is required, but only about 20 percent as much chlorine as used in standard chlorine methods. In other words, chlorine use is reduced by 80 percent by having an ozone kit installed on the filter system.
The salt treatment method generates its own chlorine. A generator takes the chloride from salt and uses it to kill germs. Hearing “salt water” makes us think of the saltiness of ocean water, which once you’ve been dunked, you remember tastes strong and makes eyes burn. But that’s not so. The required salt concentration in the chlorine generator pool system is only about one teaspoon per gallon, less than the salt in a human tear. Pool water purified by this method also softens the water.
A point to compare between salt and chlorine is that once chlorine has combined with the impurities in the water, that chlorine is no longer active: more chlorine must be added to combine with newly arriving impurities. With a chlorine generator using salt, the chlorine concentration stays fairly constant.
Bromine Bromine is also a strong chemical. It is chlorine-based, but in the pool it acts differently. When bromine combines with bacteria and contaminates in pool water, the bromine remains active while chlorine loses power.
One of the procedures of treating a pool with the chlorine or bromine methods sounds alarming. It’s called the “shock treatment.” This is a periodic mega dose of chemical, as much as 15 times the regular treatment. The shock treatment is to re-establish a positive level of free chlorine.
When you shock a bromine pool, the shock treatment only burns off the harmful contaminants, leaving a good portion of the bromine behind to continue working in the pool water. The remaining bromine is available to sanitize the pool again. The result is that less bromine is necessary to sanitize a swimming pool than chlorine.
Some pool owners prefer bromine because the chemical is usually much less irritating to the skin and eyes; however, bromine is chlorine based, and it will not help people who are allergic to chlorine.
Most often, a UV light system is an auxiliary to another system. UV disinfection works in combination with the pool’s filter system. The pump draws water from the pool to the filter. After the water is filtered, it passes through a cylinder chamber containing a UV light. It is these high-energy light waves that destroy the microorganisms.
While the UV system itself does not rely on chemicals, some chemical treatment is necessary to keep water sanitized. Since only a fraction of the pool water is passing through the UV cylinder at a time, the opportunity remains for more contaminants to grow elsewhere in the pool. However, the benefit of using the UV system is that it reduces the amount of chlorine required by up to 70 percent.
So which one is the best?
Each of us is the judge of the best solution for our own family pool. Our first responsibility is to understand that pool maintenance applies the science of chemistry and that heavy use of chlorine is not necessarily the best answer—for our children or the environment.
Karen Childress is the Environmental Steward Manager for WCI Communities.
Source: by Karen Childress
Date: 2007/05/27 01:15:00 GMT-7