Pool Chemical Glossary

Algae is a breathing plant that flourish in pools, where they get lots of sunshine, carbon dioxide and heat. Algae is typically green, but it may also be yellow, mustard, black or blue-green.

Algaecides are chemical products designed to kill algae.

Also called algae inhibitors, works by preventing algae from growing. An algaecide in contrast is used to eliminate existing algae.

Alkalinity is the amount of carbonates, bicarbonates and hydroxides in water.

Dangerous organisms found in pool water. Some bacteria can cause infectious diseases.

Balanced Water
Balanced water results when the pH, Total Alkalinity, Calcium Hardness, Dissolved Solids and temperature are all in the right proportion.

The name for a new non-chlorine based sanitizer. Biguanides are the only non-halogen sanitizer available for pool and hot tub use. Biguanide is also commonly used as a mild disinfectant in contact lens solutions, hygiene products and hospital bandages.

A sanitizer often used in hot tubs and indoor pools. It is effective in hot water and cannot be stabilized.

Calcium Hardness
A measure of the amount of calcium (dissolved) in the water.

Chlorine in many forms is a chemical used to sanitize water in pools.

Chlorine Demand
The amount of chlorine needed to kill bacteria, algae and other organisms in pool water. Once the chlorine demand is fulfilled, the water will be in an appropriate condition until additional contamination occurs.

Combined Chlorine
It measures the chlorine that is tied up or has already attached itself to other molecules or organisms. Because it is not free it cannot sanitize the water.

Also called stabilizer or cyanuric acid. It is a chemical that protects chlorine from the diminishing effects of the sun.

Cyanuric Acid
A chemical that protects chlorine against loss as a result of the sun. It is the ingredient commonly found in stabilizer and conditioner.

Free Available Chlorine
The amount of active chlorine remaining in water. Because it is not combined with anything it is ready to kill organic material.

An ionizer is a device that emits metal ions. Cooper and or silver ions are often used in pool ionization systems because copper is a known algaecide and silver kills bacteria.

Mineral Purifiers
Are similar to ionizers although they do not use electricity.

Muriatic Acid
A solution used to lower pH and or total alkalinity that is very corrosive and caustic.

Non-Chlorine Shock
A granular form of potassium permonosulfate that oxidizes microorganisms, contaminants or chloramines.

The burning up of unwanted organic waste found in pool water.

Ozone molecules are known to be a very effective sanitizer. Ozone generators and ozonators create this molecule to help sanitize water.

The scale of water acidity and basicity from 0 to 14. A low pH causes bather discomfort and corrodes equipment. A high pH can cause scale formation and cloudy water. The desired range is 7.2-7.6 and most ideal between 7.4-7.6.

A chemical agent used to eliminate unwanted bacteria and contaminants from water.

Shocks are products used in shocking or shock treatment. Shocking refers to raising the level of sanitizer so high that breakpoint chlorination can be attained.

Soda Ash
Used to raise pH.

Sodium Dichlor
Also called dichlor, it is a form of chlorine that is stabilized with cyanuric acid.

Also called conditioners, it can be added directly to your pool to enhance the chlorine's effectiveness. Cyanuric acid is already added to certain products called stabilized chlorine.

Total Chlorine
The sum of both combined and free chlorine levels in the water.

Advertiser Links for Pool Sanitizers
Swimming Pools 101