Glossary of Swimming Pool Terms and Definitions

Common swimming pool terms and definitions

Swimming Pool Glossary

Confused about swimming pool terminology? Below are some common pool terms alphabetized from A to Z to help you:

  • Algae: Pool algae are the one celled plants that can turn your pool green. Green algae is one of the most common types of algae, but there are a few others: mustard, pink, and black. Black algae is often seen in areas where there is poor circulation (dead spots or dead zones) and on the pool wall. It is very difficult to get rid of. Regular pool wall brushing helps prevent growth. It can be controlled by using algaecides.
  • Backwashing: Process where the water is reversed from the pump and the pool discharges water, cleaning the filter and ‘discharging’ pool waste. Common to diatomaceous earth (DE) or sand filters.
  • Bromine: A chemical compound used to sanitize and disinfect swimming pools. It is similar to chlorine.
  • Calcium Hardness: The sum of all calcium dissolved in the pool water. Ideal levels are 100-400 ppm. A high calcium hardness can cause scaling. This is minimized through the use of sequestering agents that bond with calcium and make it more water soluble.
  • Chlorine: A chemical compound used to sanitize and disinfect swimming pools.
  • Circulation: The process of circulating or moving the water through the pump and filter and returning it to the pool
  • Clarifier: A liquid chemical added to the water to turn smaller particles into larger ones and help clear your pool. This allows them to be removed by a pool filter.
  • Coping: The lip around the top of a pool or hot tub wall.
  • Diatomaceous Earth: Also known as DE, it is a porous silica rock in the form of a white powder from fossilized one-celled algae. It used in some swimming pool filters (D.E. filtration systems) as a highly effective filter medium.
  • Filter: Removes dirt, debris, and matter from the swimming pool. There are 3 types. Cartridge, sand, and diatomaceous earth (DE).
  • Heater: Pool device that heats a pool, spa or hot tub.
  • Motor: The pool motor is a device at the heart of the swimming pool circulation system, run by electricity and drives the pool pump.
  • Ph: The letters ‘Ph’ stand for ‘Potential of Hydrogen’. It measures the degree of acid or base in water and is on a scale of 1-14. A solution with a Ph below 7 is considered acidic, and above 7 is considered base. Regular tap water has a Ph of 7. Optimal pool water Ph is between 7.2 and 7.8.
  • Pump: The pool pump pulls the water from your skimmer and drain and then circulates it through the filter by pushing it back through the returns in your pool.
  • Salt Pool: A salt pool usually refers to a salt chlorine generated pool or a pool that utilizes a salt chlorine generator, where chlorine is produced by electrolysis from contact with a ‘salt cell’.
  • Scaling: Condition where sharp ridges or scales are formed inside the pool on the surface floor and walls due to an overabundance of calcium in the pool water.
  • Shock: Pool shock or super-chlorination is when chemical compounds like Dichloroisocyanuric Acid (Di-chlor), lithium hypochlorite, calcium hypochlorite, are added to the pool water to destroy bacteria, algae and other microorganisms and to help maintain the proper amount of chlorine in your pool. Because body oils, sweat, urine and other organic compounds get eaten up by chlorine it is necessary to shock your pool weekly depending on swim load.
  • Skimmer basket: Sits inside the pool skimmer housing. It is where the dirt and debris including leaves is deposited after skimming the surface of your pool.
  • Skimmer: Removes dirt and debris including leaves, hair, suntan lotion from the top surface of the water in your pool. Includes the skimmer cover, weir and weir door (flapper), and skimmer basket.
  • Test strips: Color strips that contain a chemical reactant that allows you to take a reading on a swimming pool to help balance the water. Usually includes reading for: Ph, Free Chlorine, Total Chlorine, Bromine, Total Hardness, Total Alkalinity, and Cyanuric Acid.
  • Total Alkalinity: Helps to control the Ph in the swimming pool. Refers to the ability of the pool water to resist a change in the Ph level. Ideal level is 80-120 ppm (parts per million).
  • Total Dissolved Solids (TDS): This is the sum of all materials (chemicals, minerals, oils) that are dissolved in pool water. The higher the concentration of TDS the harder your pool has to work to keep clean and the more difficult it is to maintain water balance. Your pool water should be changed every five years to prevent a high TDS.
  • Weir (Also known as skimmer weir or flapper): Part of the skimmer housing that allows the flow of water into the skimmer.
  • Virginia Graeme Baker Act: Known as the The Virginia Graeme Baker Pool & Spa Safety Act (P&SS Act) in memory of a young girl that died in a drowning accident when she was trapped by the suction of a spa’s drain. The act establishes standards regarding swimming pool and spa safety, more specifically the equipping of public pools and spa’s with anti-entrapment devices and minimum state regulations for swimming pool safety.

Additional Resources

Looking for more information? Check out these additional resources for articles and terminology.

  • National Swimming Pool Foundation
    4775 Granby Circle
    Colorado Springs, CO 80919 United States
    Telephone: (719) 540-9119
  • The Association of Pool & Spa Professionals
    2111 Eisenhower Ave.,
    Alexandria, VA 22314
    Phone: (703) 838-0083

About Us

Putnam Swimming Pool Service is a family owned and operated residential swimming pool and spa cleaning, maintenance, repair, and renovation company. Our specialty is gunite and concrete in ground swimming pools. We have been proudly servicing Fairfield County, CT and Westchester County, NY since 1992.

At Putnam Swimming Pool Service, our goal is to help ensure that your pool is clean, safe, and beautiful.

Have questions? Drop us a line on our contact page.