Chloramines (combined chlorine) & Chlorine Demand...

Continued from page 1  

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

In the Spring of 2006 a new, state of the art Chlorine Demand test station (BioGuard®'s Accu-Demand 30) was made available to us.  It is virtually 100% accurate.  Compared to the old method, results are now available in about 30 minutes rather than 24 hours.  This gets the problem rectified immediately, as opposed to waiting an additional day or 2 when the results would be ready and more chloramines form.  The Accu-Demand 30 will be the best available method to accurately perform a Chlorine Demand test on the market.  If you are one of our “out of town” customers, you can send a water sample for testing.  There will be a small fee for this service; however we will call you with the results and recommendations within 3 hours of our receipt of the sample. 

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 spa or hot tub, 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 (orthotolodine 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 (uses separate tests for Free Chlorine as well as Total Chlorine).  Most spa or hot tub owners rely on single use test strips that are, overall, pretty accurate when it comes to measuring the level of Free Chlorine.

Controlling small amounts (under 2.0 ppm) of 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 spa or hot tub is the preferred preventative procedure.  Just because the spa water looks good doesn’t mean that everything 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 are purely speculative and have not been scientifically proved.  The 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; known as "chloraminization".  Chloramines were and are known to be more stable and “persistent” as we’ve already mentioned.  Chloramines do 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.  We are instead looking at 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.

Continue to page 3

Translate this page or any of our pages using the tool below :