Stabilizer:  |  Intro
 Testing  |  Adjusting  | 
The Debate

Stabilizer – Adjusting

Stabilizer (Cyanuric Acid)

If the stabilizer is too low, then the solution is fairly simple:  Add the
required amount of stabilizer to bring the level up.  If you are using stabilized tablets, then we recommend bringing the level up to 30 ppm.  It will continue
to rise from there due to the stabilizer in the tablets.  If you are using non-stabilized chlorine (such as calcium hypochlorite or a salt system) then adjust the
stabilizer to 80 ppm because it will continue to go down due to splash-out or backwashing or other water loss.

If the stabilizer is too high, you have a couple of options.

Option 1 –  Drain and Refill – if the stabilizer level is too high, you can drain
it and refill it with fresh water.  If you are concerned about health hazards related to the high stabilizer levels, then you should use this approach.

Should you drain halfway or completely?  That depends on the actual stabilizer
level in the pool.  If you already have a stabilizer level of 150 ppm, draining it halfway only gets it down to 75 ppm and you will be back up over 100 ppm in just
a few months.  If your stabilizer level is 100 ppm, you can get it down to 50 ppm by draining halfway. 

Some pools simply cannot be drained completely without risking problems.  This would be true of fiberglass pools which
do not have much of a self-supporting structure.  You risk a cave-in if you drain a fiberglass pool, so you need to drain only partially.

How much does it cost to refill a pool?  In the Dallas area, water costs around
$3.00 per thousand gallons, which means that if you refill a 25,000 gallon pool, it costs about $75.00.  This does not include the sewer charges which are often
calculated based on water usage, but many water depts will refund the sewer charge on the amount of water that it took to fill the pool.  Consult with your local
water company for pertinent rates and policies in your area.

If draining and refilling a pool is not an option for whatever reason, there is another approach:

Option 2 –  Chemical Treatment – the use of bromine salts has been very effective
in dealing with the impact of high stabilizer levels.  This is not nearly as simple as draining and refilling, but for the professional, it is something that he
needs to be able to utilize as needed.

How does it work?  When chlorine goes into the pool water, it takes the form of
HOCl.  If the stabilizer level is too high, it slows down the reaction of the HOCl to the point that it loses a lot of its effectiveness.  When you add
bromine salts to the water, you change the formulation of some of the sanitizer from HOCl (hypochlorous acid) to HOBr (hypobromous acid) which is not affected by the
stabilizer.  An initial treatment of bromine salts plus shock followed by subsequent maintenance doses will help to keep an active edge on the chlorine. 

Since the HOBr is not affected by the stabilizer, it is very effective against algae and germs, but it is also more quickly
dissipated by sunlight.  After the initial treatment, the chlorine usage of the pool will approximately double for about 2 weeks, after which it will return to

Treating a pool with Bromine Salts

 Treatment Type

Gallonage of pool or spa




Initial Treatment

4 oz bromine salts and shock with 20 ppm chlorine shock.

8 oz bromine salts and shock with 20 ppm chlorine shock. 12 oz bromine salts and shock with 20 ppm chlorine shock.

Maintenance Treatment

2 oz bromine salts every two weeks.

4 oz bromine salts every two weeks. 8 oz bromine salts every two weeks.

Note:  When doing the initial treatment, slurry the bromine salt treatment and pour into the pool, then
slurry the shock and pour into the pool.  Brush down any visible algae thoroughly.  After the initial treatment, test the chlorine levels daily and
feed enough chlorine to maintain a consistent chlorine level.

Be aware of the fact that high stabilizer level is not the only problem that can cause algae difficulties.  High levels
of phosphates can also be a strong contributing factor for yellow algae.  It may be necessary to add a phosphate reducing chemical to pool if this is the case.