How do you measure stabilizer in pools?

Answer 1

Stabilizer, in a chlorinated pool, normally refers to the chemical that slows down the rate at which the chlorine leaves the pool. Chlorine is only working while it is leaving the pool, referred to as Free chlorine, as opposed to Total Chlorine.

Stabilizer normally takes the form of Cynuaric Acid and is found in all the chlorine products except powdered chlorine. The aim is to ensure it does not leave the pool too quickly.

This is why only powdered chlorine should be used for 'shocking' the pool. It provides a high dose of chlorine which dissipates relatively quickly. Pools should be shocked on a regular basis to effectively restart the water balancing process. It is not unusual for the Ph to take a dive after shocking. The main reason for shocking is to get rid of the bacteria which has mutated and become used to the continuous level of chlorine that is not showing much change in level over a period of time.

For those of us that use test strips it is referred to as stabilizer or Cynuaic Acid, and a normally good result is in the area of 30-50 ppm. By definition, if it is measured too low then chlorine levels will drop to quickly and tablet consumption may also be increasing to keep up. The other factors affecting the way chlorine leaves the pool is temperature, water agitation and sunshine.

Cynauric Acid is cumulative to the pool and the only way it gets out of the pool is by regular back washing, it does not evaporate away.

It should also be noted that a high level of Cynauric Acid will stop chlorine leaving the pool and therefore the pool is not being sanitised. It is the answer to the question; 'Why is my pool going green, I have good levels of Chlorine'? - Answer, as above, it's in the pool but cannot get out. Do a partial water change to lower the level of Cynauric Acid and shock it.