FROG Water Care Experts Glossary of terms

Scale that forms from calcium compounds when pool water is too alkaline, calcium hardness is too high or total alkalinity is too high. These hard deposits accumulate on pool surfaces and equipment.

Also called "Calcium Up" it is a soluble white salt used to raise the calcium hardness of the pool water when required.

A measure of the level of calcium and magnesium pool and spa water. Helps to determine how scaling or corrosive the water is. It is especially important to monitor calcium hardness in pools with a plaster finish. The ideal range is from 200 to 400 ppm; the minimum level is 150 ppm. One of the basic water tests necessary to determine water balance.

The sanitizing or chlorinating agent using calcium as the carrying salt for application. It's a granular product that is not sun stable. It tends to increase pool water pH. It is usually used for superchlorination. It usually contains 65% available chlorine.

Filter with a pleated element that traps debris. Looks like a giant oil filter.

A mechanical device in a pipe that permits the flow of water or air in one direction only.

Copper algaecides that contain a special ingredient to prevent the copper from staining the pool walls and bottom or producing colored water.

(Pronounced KEY-late) Also called sequester. A chemical that binds up metals. Used to prevent metal staining and colored water.

Any of several types of devices that dispense chemicals into the pool or spa water at a predetermined rate. Some dispense chlorine or bromine while others dispense pH-adjusting chemicals.

Smelly compounds formed by combining with nitrogen compounds from human waste such as perspiration, urine and skin proteins. Chloramines have an objectionable odor of "too much chlorine" and can irritate swimmers' eyes and skin. Cured by proper shocking.

A mechanical or electrical devise for dispensing chlorine at a controlled rate. Most often a canister or floater filled with tablets of chlorine.

The most widely used bacteria-killing agent for recreational water treatment. A sanitizer and an oxidizer. As a sanitizer it kills bacteria in pools. As an oxidizer it burns off organic matter and kills algae.

The amount of chlorine required to control bacteria, algae, and other contaminants in swimming pool water. Once the chlorine demand is satisfied, the water will be in a sanitary condition until further contamination takes place.

A chemical compound that when used in conjunction with chlorine makes the chlorine perform better as an algaecide.

The most pure form of chlorine, which can only be applied to pools by trained professionals. It is not an appropriate sanitizer for spas.

An electrical device that generates chlorine from a salt solution in a tank or from salt added to the pool water.

A term used to describe a condition where chlorine has slower killing speed on algae, bacteria and burning out organic matter. It is caused by over-stabilization or excess cyanuric acid.

A chemical used to make chlorine harmless. Used in test kits to counteract the bleaching effect of the chlorine or bromine in order to increase the accuracy of pool water tests. Sold as chlorine and bromine neutralizer, it is used to control excessive amounts of chlorine or bromine, so the high levels will not affect swimmers.

The amount of chlorine that remains in the pool or spa water after the chlorine demand has been satisfied. See also Free Available Chlorine.

The flow of water in a swimming pool or spa. Ideally the circulation should leave no dead spots (areas of stagnant water).

A chemical used to remove haze in the water. Usually works by causing small particles to join together so the filter or vacuum can pick them up. Also called coagulant or flocculent. There are two types; inorganic salts of aluminum (alum) or water-soluble organic polyelectrolytes.

A chemical compound added to water to gather suspended particles together for filtration. See Flocculating Agent.

A test where a reagent causes a change in color when reacting with the specified chemical. This color is then compared to a color standard chart.

Chlorine that is in combination with ammonia, nitrogen or other organic compounds. See Chloramines

Chemically, conditioner is cyanuric acid. It slows down the degradation of chlorine in the water by sunlight. Minimum level is 10 ppm. Too much does not slow down chlorine activity or effectiveness. Conditioner does not protect bromine from sunlight.

The material that joins the pool to the deck. Made of concrete, aluminum, plastic, brick or wood. Commonly concrete on concrete pools and aluminum on vinyl pools.

It is one of nature's elements. It is also used for various parts of equipment and plumbing in swimming pools and spas. Corrosive water caused by misuse of chemicals, improper water balance, or placing trichlor tablets in the skimmer can cause copper to be dissolved from the equipment or plumbing and deposit the precipitates on hair, fingernails or pool walls. High levels of copper can also cause green water. Copper is also used as an algaecide. Maximum level is about 0.2 ppm.

A chemical compound that contains element copper. Copper sulfate was one of the original copper algaecides. Too much copper in the water can cause green-colored stains. Newer copper algaecides contain an ingredient that prevents the copper from staining but does not affect the copper's ability to kill algae. These special copper algaecides are called chelated copper algaecides.

The etching, pitting or eating away of the pool or spa or equipment. Caused by improper water balance, misuse of acid or acidic products or from soft water.

A water condition of low pH (acid condition) that can corrode metal pipes, pool fixtures and pumps.

A plumbing fitting that is used to connect two pieces of pipe.

A cover used on pools, spas and hot tubs that rests on the lip (coping) of the pool or spa deck - not a floatation cover. Used as a barrier to swimmers and bathers, and for maintenance and thermal protection.

A cover that, when placed on the water's surface of a pool, spa or hot tub, increases the water temperature by absorption and transmission of solar radiation; reduces evaporation and prevents wind-borne debris from entering the water.

A cover that is secured around the perimeter of a pool, spa or hot tub that provides a barrier to bathers and debris when the pool, spa or hot tub is closed for the season.

Also called conditioner and stabilizer. Stabilizes chlorine. Can be part of the chlorine, as in stabilized chlorine or can be added separately if using unstabilized chlorine. Helps prevent deterioration of chlorine from heat or sunlight. Avoid high levels (75 ppm or above) which can cause discoloration, odors and other problems. Recommended level = 25 ppm.