Brominated pools tend to exhibit
different characteristics than those of pools using traditional
chlorine sanitation. Pool operators need to know the nuances of
working with bromine in order to maximize oxidizer efficiency,
improve the overall swimmer experience, and minimize the associated
No more breakpoint
One advantage bromine has over more traditional programs is that it
retains active efficiency after reacting with nitrogenous swimmer
wastes. Unlike chloramines, bromamines are disinfectants with
activity that rivals that of either free chlorine or free bromine.
In addition, bromamines do not produce the noxious odors and
associated eye and skin irritation attributed to chloramines.
Therefore, “breakpoint” sanitation is unnecessary in
bromine pools, as bromamines maintain oxidizing activity in the
water while retaining aesthetically pleasing qualities.
Though bromamines retain oxidizing activity in the water, and do
not produce the infamous “chlorine” odors associated
with chloramines, frequent oxidation for a bromine pool is still
important. There are two reasons for this:
First, supplemental oxidation facilitates the regeneration process
of the bromide ion (Br-). Once spent by oxidizing organic material
or inactivating microorganisms, the majority of active bromine
reverts to bromide. This regenerative process is unique to bromine
in typical swimming pool water, and is how spent bromine is
reactivated into its disinfecting form (OBr-).
Therefore, frequent oxidation by either a chlorine or a
non-chlorine shock such as potassium monopersulfate is necessary to
convert the bromide.
Second, oxidation is still required to break down some of the more
complex organic wastes introduced by bathers. Generally, bromine is
less powerful than some of its oxidizer counterparts, so it’s
important that a user continue to shock frequently to rid the water
of organic wastes that can exhaust sanitizer and give the water a
Higher pH tolerance
Bromine dissociates at a higher pH range than chlorine. What this
means is that it remains in its active form at higher pH, yielding
nearly twice the active efficiency of chlorine at a pH of 7.5, and
more than two and a half times the active efficiency at a pH of
This is one reason why bromine is more common in spas, due to the
natural tendency of spas to operate at a higher pH level as a
result of the volatility of carbon dioxide when running the
In addition to its oxidative properties, bromine exhibits superior
algaecidal characteristics. Studies have documented that free
chlorine can behave as an algaestat at a concentration of 0.2 ppm,
meaning that it will control algae and prevent growth. However,
bromine behaves as an algaecide at a concentration of 0.2 ppm,
meaning that it can kill algae to reduce the overall algal
Due to these algaecidal properties, bromine pools that have
recurring issues of resistant or mustard algae typically operate
more efficiently and with less trouble through a full season.
It’s a helpful option for those customers who are having
difficulty eliminating their algae issues.
Bromine is a great option for indoor pools due to the activity and
volatility resistance of the bromamine byproducts. The reason
bromine pools tend to have reduced odor is due to the lower vapor
pressure properties of bromamines. The benefits of this behavior
include reduced respiratory irritation to swimmers and less
corrosivity to the ventilation system.
However, ventilation systems are still critically important for
indoor pools, even ones using bromine. Ventilation systems manage
indoor humidity to help limit heat loss from the pool. They also
serve as an
exhaust for other gasses that volatilize due to the oxidation
process of organic wastes by supplemental oxidation.
Since bromine cannot be stabilized against the degrading effects of
certain bands of UV light, as chlorine can, it has typically been
discounted for use in outdoor pools. However, there are methods for
managing bromine to mitigate these degrading effects of UV.
Implementation of a continual feed system helps users manage their
bromine degradation. Studies have shown that operating a pool at
the lower end of the recommended sanitizer range reduces the amount
of bromine subject to degradation: The less bromine you keep in the
pool, the less is degraded by sunlight.
The half life of bromine is approximately one hour, which means
that it will lose about half its oxidizing strength for every hour
it is exposed to external sunlight. Therefore, a pool operating at
3 ppm will lose 1.5 ppm of bromine; as opposed to a pool operating
at 5 ppm, which will lose 2.5 ppm of bromine over the same
60-minute time period.
Adjusting your feeder to maintain the lower end of the range will
minimize the amount of bromine that feeds into the pool. In
addition, weekly feeder top-off practices have resulted in a high
rate of success.
Keeping a full feeder facilitates a more constant feed rate; as
tablets erode, the amount of bromine fed to the pool is reduced.
Maintaining a full feeder gives an operator greater control over
the pool and thus allows for a minimal loss of sanitizer to UV
Balance is important for swimming pools, whether it’s proper
water balance to protect the swimmers, surface and equipment; or
balancing the benefits of pleasant swimming experiences and easy
maintenance against the costs.