CHLORAMINES... COMBINED CHLORINE

When nitrogen enters a pool, the chlorine is attracted to it. When the nitrogen and chlorine molecules come in contact, they form a new compound, a combined chlorine called a chloramine.

THE EFFECTS OF NITROGEN

Nitrogen is a colorless, odorless gas. It is a common element and part of the chemical make-up of:

• Urine
• Perspiration
• Cosmetics/lotion
• Rain
• Fertilizer

When nitrogen and HOCI combine, chloramines are formed. Chloramines are also called combined chlorine. Since the chlorine is combined with the nitrogen, it is no longer free and available to kill bacteria as effectively as Free Available Chlorine. The chlorine in these chloramines no longer function as an effective sanitizer and as the chloramines build up, several other problems can occur.

• The water smells bad, giving off an obnoxious chlorine-like smell.
• The water irritates the mucous membranes of the nose and eyes.
• The water is a little cloudy or dull looking.

HOW MUCH IS TOO MUCH?

It doesn't take many chloramines to make water cloudy and irritating. You should always keep this combined chlorine as low as possible.

Maximum tolerable combined chlorine level -- BELOW .2

(Note from Pool Emporium, Inc.: Many test kits do not include a test for combined chlorine. In the typical home test kits that do, it is very difficult to see a difference of .2! Pool Emporium, Inc. utilizes a digital colorimeter that can take this measurement to 1/100th of a ppm! Most professionals do not have this expensive equipment, but are still better able to determine this value for you just from the sheer number of tests they perform on a routine basis. As a general rule of thumb, if you can see ANY difference you should probably oxidize your pool.)

OXIDIZE TO CLEAN UP CHLORAMINES

To rid a pool of chloramines, you have raise Free Available Chlorine to a level that breaks the chlorine and nitrogen apart. This is called breakpoint chlorination. There are several ways to reach breakpoint and all involve oxidation, but not all use chlorine to reach breakpoint.

BREAKPOINT CHLORINATION - ALL OR NOTHING

Since chlorine is already used in many pools, super chlorination is often used to achieve breakpoint. However, the Free Available Chlorine (expressed as ppm) must exceed the Combined Chlorine (expressed as ppm) by a 10 to 1 ratio to achieve breakpoint.

The breakpoint ratio has to be achieved to have any effect at ail. If you do not reach the 10:1 ratio, you have only added more FAC. You have not eliminated the chloramines and, if excess nitrogen is available in the water, may have actually created more chloramines.

Consequently, to reach breakpoint chlorination you need the right products. BioGuard offers you three:

• BioGuard Lite* - A patented blend of chlorine, clarifiers, buffers and oxidizers
• Burn-Out - The most concentrated blend of all the products used.
• Burn-Out 35 - Ideal for pools with bleachable surfaces like vinyl. It does not have to be dissolved.

*BioGuard® Lite™ has not been accepted by the U.S. EPA for use as a disinfectant, sanitizer, or algicide

ACHIEVING BREAKPOINT

When you do reach breakpoint, all chloramines are eliminated. The nitrogen escapes as gas and the chlorine once combined chlorine is reduced to a chloride. The chloride is an inert chemical compound and can no longer be useful in fighting bacteria.

Breakpoint chlorination provides a number of benefits:

• The chloramines are removed from the pool.
• The oxidation breaks down wastes like body oils, perspiration, urine and suntan lotion.
• The high levels of HOCl kill some algae that may have become resistant to lower levels of HOCl.
• Any extra chlorine continues to sanitize the pool and re-chlorinate the stabilizer in the water.

HOW OFTEN DO YOU DESTROY THE CHLORAMINES?

Breakpoint needs to be performed regularly to control chloramines. If there's an excess of nitrogen-containing contaminants in the water (e.g. ammonia, urine, etc.) the nitrogen will seek out the new chlorine (being added to provide breakpoint) and form more new chloramines. Of course, that aggravates the problem instead of solving it. So you want to oxidize the water often enough so that this never becomes an issue. If a water test reveals zero Free Available Chlorine in the water and any level of Combined Chlorine, that is a tell-tale sign that there could be excess nitrogen in the water.

BEWARE!

• Pools should remain uncovered for eight hours after shocking.
• Provide adequate air circulation on indoor pools.
• Provide adequate time for breakpoint reactions to occur.

It's best to perform breakpoint on a schedule that eliminates the build-up of chloramines. That frequency is also affected by the amount of nitrogen being introduced. Some criteria affecting the build-up of nitrogen are:

• The number of swimmers
• The age and type of swimmers
• The amount of rain and ground water run-off
• The geographic location of the pool
• Exposure to fertilizer applications

Since breakpoint chlorination with Bum Out and Burn Out 35 adds a substantial amount of FAC to the water, reentry to the water should be postponed until the FAC level drops back to 3 ppm or less. Depending on the level of FAC you needed to reach breakpoint, it may take eight hours or more before reentry is advised.

BioGuard Lite* makes it more convenient to remove chloramines and maintain good water quality on a regular basis. This special blend of oxidizers and clarifiers is formulated to be added every week. Weekly application allows for the constant removal of chloramines and waste. In addition, BioGuard Lite provides routine flocculation and buffering agents for clearer, more pH balanced pool water.

Since a lower level of chlorine is being added, reentry into the water can occur more quickly, typically within 15 minutes.

*BioGuard® Lite™ has not been accepted by the U.S. EPA for use as a disinfectant, sanitizer, or algicide

NON-CHLORINE BREAKPOINT

OXYSHEEN®

Chlorine is not the only oxidizer that destroys chloramines. Oxysheen destroys chloramines. Any Oxysheen that's added will eliminate as many chloramines as it can. Though breakpoint IS occurring, it IS NOT an all or nothing reaction. This treatment a good choice when the pool is indoors.

SO WHAT IF...

The Combined Chlorine is too low... (below .2 ppm) Be happy! This is the kind of low reading you want. The water looks good, smells good, and is properly sanitized (if FAC is between 1 - 3 ppm). (NOTE FROM POOL EMPORIUM, INC.: In Florida, we could never keep a clear, blue pool with a FAC [Free Available Chlorine] level of 1.0 ppm, when there is no other supplemental sanitizer present. We suggest 1.5-3.0 in the "winter" [November through March] and 2.0-3.0 in the "summer" [April through October].)

The Combined Chlorine is too high... (above .2 ppm) The water will look hazy. It will irritate the eyes and nose, and the sanitizer will be less effective.

• It's time to provide a breakpoint solution to the water.
• Use BioGuard Lite*, if Combined Chlorine is .5 ppm or less
• Use Burn Out or Burn Out 35, if Combined Chlorine is higher than .5 ppm, applied at a rate to provide breakpoint chlorination. (10:1 ratio of FAC: Combined Chlorine)

If there is no FAC, or the Combined Chlorine is extremely high, there may be an excess of nitrogen in the water. Use Oxysheen to reduce the chloramines or consider draining a portion of the pool water.

*BioGuard® Lite™ has not been accepted by the U.S. EPA for use as a disinfectant, sanitizer, or algicide.

A WORD ABOUT POLYSHEEN

When a compound like is used to oxidize a pool, Total Chlorine readings will be falsely high for up to 72 hours.

The information on this page has been provided courtesy of BioLab, Inc. ©1998