The following information was found at another website which we agreed to purchase because it is well written and understandable.  We think you will find it interesting as well as helpful.

One of the most common causes of water related problems in swimming pools is the presence of chloramines.  Chloramines are often referred to as “combined-chlorines” because they are molecules formed by the combination of chlorine in the form of Hypochlorous Acid (HOCl) and organic wastes (saliva, perspiration, urine) in the form nitrogen or ammonia.  Chloramines produce the “chlorine odor” that many people do not like (tear gas is a form of chloramine).  When people complain of “too much” chlorine, it is always the case of combined chlorine or chloramines causing the foul odor.

But foul chlorine odors are just the ugly mask of the underlying problems present in swimming pool water.

Chloramines are the root of a lot of problems in pool water.  Chloramines cause problems because of their stability and persistence.  This stability and persistence forms additional Chloramines.  This is chlorine demand (consumption) at its finest.  (Consumers complain that they “just shocked” the pool but there’s no chlorine showing when tested.) As more chlorine is added without reaching breakpoint, more chloramines are formed exacerbating the problem leading to what I’ll call “obvious problems” such as cloudy water or algae growth.  Homeowners and/or pool dealers unfamiliar with chloramines and chlorine demand begin treating the symptoms (cloudy water or algae) rather than dealing with the root cause – especially after the second or third treatment.  Without the knowledge of chloramines & chlorine demand, consumers may not receive the help they need.

Chlorine demand testing stations aid greatly in determining the appropriate amount of chlorine needed to reach breakpoint chlorination – usually recognized as 10 ppm FAC (free available chlorine) to correct each 1ppm of combined chlorine.  Failing to realize this amount actually contributes to the chlorine demand problem as more chloramines are formed.  We often hear the consumer complain that “my pool guy told me to put in a double dose of shock to treat my cloudy pool.”   That amount may indeed fall VERY short of the actual need.  When a chlorine demand test is performed, it is often seen that a dose of 10, 20 or more times of chlorine shock is needed to reach breakpoint chlorination.  That means potentially adding 40, 50 or more pounds of shock (in the form of cal hypo) at one time -- Yes, at one time.  If you try spreading it out (even over a few hours) you’ve defeated the cure.

We describe the problem this way to our customers in regards to reaching breakpoint:  Reaching breakpoint chlorination is an “all or nothing” proposition. Think of it as trying to jump the Grand Canyon in a single bound; you can’t “come close”.  You MUST reach the other side FIRMLY.  You can’t “almost make it.”  Whether you’re 2 inches short or 100 feet short, you’re still short. 

This is where our constant reminding of consumers of the need to weekly shock their chlorine or bromine pool.  Weekly shocking during the entire time the pool is open & operating will greatly reduce the potential of chlorine demand or consumption.

Another facet to the chlorine demand and chloramines problem is the misconception that the pool “smells of chlorine”, therefore (in the novice’s mind) “I’ve got too much chlorine or too many chemicals present in the water, “ and they stop adding anything to the pool, effectively ignoring the problem. Testing goes out the window; pH and overall water balance go out of balance.  The pool owner is not convinced that their true problem is a “lack” of chlorine and particularly FAC.  This is especially true if the homeowner or pool operator is using OTO (will produce results for Total Chlorine only, using yellow color standards, not differentiating the difference between FAC and chloramines present) for chlorine testing as opposed to the more accurate DPD (using pink color standards) method (tests for Free Chlorine as well as Total Chlorine).

Controlling small amounts (under 2.0 ppm) chloramines is relatively easy.  Shock the pool with a good-quality granular chlorine or use an oxidizing compound containing potassium mono-persulfate.  Mono-persulfate “shocks” are great because they don’t add additional chlorine that may contribute to further chloramine formation.  We have found that even when there are larger amounts of chloramines present, the mono-persulfate works well in reducing the chloramines by oxidizing these wastes and releasing the combined chlorines.  Breakpoint chlorination often-times becomes simpler to achieve.  Again, weekly shocking of the pool is the preferred preventative procedure.  Just because the pool water looks good doesn’t mean that very thing is balanced and working properly.

A lurking problem? 

Another potential area or source of the chloramine problem may be something we as dealers or homeowners have no control over.  The following comments and questions that I pose are purely speculative and have not been scientifically proved.  My premises are based on over 30 years of experiential observation and hopefully common sense.  The chloramine problems that we’ve been discussing in this article have become more prevalent each passing swimming season over the past decade.  There’s a greater frequency and severity of the chloramine issue.

 In the early and mid 1990’s, the nation’s public water suppliers began switching to using chloramines in the water sanitizing process.  Chloramines were and are known to be more stable and “persistent” as we’ve already mentioned.  Chloramines due a good job controlling normal bacteria and “stuff” in water. I will not discuss the reasons why chloramines are the preferred and even mandated form of bacteria control in potable water systems.  That is a discussion for the scientist and politician.  As a layman, I am looking at my daily observations.

 Throughout the 1990’s we heard the cry of “get of rid of chlorine!”  Chlorine was given a bad rap.  Mainly from people who don’t know what they’re talking about.  After all, how do you ban an element?  People didn’t like the so-called taste of chlorine in their drinking water. Given a choice of coli-form bacteria or a slight chlorine taste, I’ll take the chlorine taste. Chlorine has undoubtedly saved thousands, and I dare say millions, of lives around the world in purifying water.  We see what untreated water looks & smells like and its devastating effects.  This is especially poignant in the wake of Hurricanes Katrina and Rita.

 These are my observations over the past 10 - 15 years regarding swimming pools:  Increasing frequency and severity in treating chloramines in swimming pool water; Increased questions of chlorine demand or consumption; More frequent consumer complaints of skin rashes or eye irritation when using a pool, spa or hot tub. In the late 1980’s and early 1990’s, “pink slime” and “white water mold” were being blamed on biguanide usage, until it was noticed that there was this pink stuff coming from the garden hose.

 From a potable drinking water standpoint these are my observations.  Tap water rarely “smells” of chlorine. A need to more frequently clean my bathroom or sink areas.  The toilet always seems to have a ring.  Often times when the garden hose is turned on, a “glob” of icky, pink stuff comes out.  What’s going on? 

Now we tell our pool or spa customers to run the water for a minute or two to flush out the garden hose before adding that water to the pool, spa or hot tub (now we’re “wasting water,” a very valuable resource.  We don’t want the “bio-film” in the pool or spa, but what about the chloramines coming in? Do we have a potential situation where pathogens, that may be present in the drinking water, are being killed but then their “waste” is not being oxidized? Why is there a build-up of bio-films in garden hoses, sinks, toilets, piping? 

Are chloramines good oxidizers?  No. As pool & spa professionals, we know the necessity and advantage that regular oxidation performs; we more fully get rid of ALL of the stuff that is a potential contaminant.  I base my hypothesis on the fact that if you add more chloramines to pool or spa water, you will form even more.  It’s a vicious circle.

The pool, spa or hot tub owner and user must understand these facts and act accordingly to protect not only his or her investment, but also the health of the users.

Is there a correlation? In my opinion, possibly. Unfortunately, it will take many years of testing & “scientific” observation before we have a conclusive answer.

In the meanwhile, the local public water suppliers tell us: “Chloramines will not affect swimming pools; you will still need a free-chlorine residual to retard algae and bacterial growths in pools.” (http://www.casitaswater.org/water%20utility/chloramines.htm  Ventura, CA)

At the same time, in the same article, there is the statement that “[a] small amount of ammonia used to form Chloramines may affect rubber and some manufacturing processes. Chloramines may cause rubber linings of water lines to disintegrate over a period of time.”

Other comments published by other water authorities such as in Pasco County, Florida, provide similar information. (http://pascocountyfl.net/utilities/water/Chloramine.htm) 

Is there a matter of public health?  I don’t know.  I have not investigated nor do I have the specific expertise to probe those more far-reaching consequences.  Over the years I have tended to trust, almost without question, our public officials.  I believe they are constantly doing what is in all of our best interests.  I believe this because they have families and loved-ones who are drinking this water also.

My purpose in writing this article is to simply address some possible correlations that may directly affect my customers’ pools, spas & hot tubs and their families and friends who use them.  People in both the pool & spa industries and public health & water supply need to work together to address these issues.  Although the “use” of water for filling pools and spas is relatively small (practically speaking), our impact is great across the country.  Consumers are constantly looking for answers to simply their pool and spa care needs and expense.  Consumers also want to be assured of their personal health and safety regarding both swimming, soaking and drinking.

Used with permission.