Why Do Pools Need to Be Treated?
There are three primary areas to consider in pool maintenance: cleaning, circulation and water filtration. In this article we will focus on the cleaning chemicals and upkeep of your pool’s water. For information on the other aspects of pool upkeep, check out our article on general pool maintenance, How to Maintain a Pool.
Failing to properly treat your pool water is not only damaging to a swimmer’ health, but it can also prove costly to the pool itself and your pool’s plumbing. The four primary areas of treating pool water are
- Correct pH balance
- Disinfecting
- Algae control
- Calcium control
As we go through our pool chemicals guide, you will learn what each of them are and their purpose in helping you have a sparkling clean pool for friends and family to enjoy.
Chlorine Pools
Chlorine pools need the addition of chlorine to ward off bacteria, cloudy water and prevent algae growth. Chlorine pools also need water balancing more often than a saltwater pool. You can assess the pH, chlorine and alkaline levels and water hardness with test strips. Testing weekly and adding the appropriate chemicals to retain an optimal balance will keep your pool water looking and feeling its best.
Saltwater Pools
Saltwater pools are gaining in popularity thanks to the reduction in irritation of skin and eyes from not having chlorine. Salt is added directly to the pool water, and using a device known as a saltwater chlorinator, water is sanitized through electrolytic chlorine generation. This leaves your pool water without the chlorine odor and water that is softer, silkier and more gentle to skin, hair, eyes and clothing. Thanks to not needing all of the chemicals associated with chlorine pools, saltwater pools can have lower maintenance costs overall.
What Pool Chemicals Do I Need?
There are four main objectives that pool chemicals are used for: to disinfect, shock, defend and balance. The following list will explain the part that each chemical plays in helping to make your pool water sparkle.
Chlorine
Chlorine is added to swimming pools to sanitize the water. It also helps to get rid of algae and break down nonliving substances like oils and organic waste. There are two familiar types of chlorine, liquid and trichlor. Liquid chlorine is a non-stabilized form that is easy to apply, thus it’s widespread use in both residential and commercial pools. Liquid chlorine is cheaper than other forms of chlorine but has a shorter effective period.
Trichlor is a form of chlorine that is stabilized to withstand ultraviolet rays. It is available in tablet form, making applying it to your home pool easy. The chlorine tablets provide a slow release of high-quality sanitizer, but you will need to check various places in the pool to ensure even distribution. For more information about pools and chlorine, see our article How to Chlorinate a Pool.
Never mix types of chlorine, store them together or allow a chlorine product to come in contact with a bucket, bag, box or dispenser used for another type of chlorine. Read, understand and follow all instructions for pool chemicals, including proper use, storage, safety precautions and protective equipment.
Water Balance
Making sure your pool’s water is balanced will provide a pleasant swimming and playing experience and will be better for you pool and equipment. Test strips and test kits can check for total chlorine, bromine, pH, total alkalinity, total hardness and cyanuric acid (CYA) levels. Setting up a regular test schedule of at least twice a week should keep your pool water fresh and clean.
Pool Shock
Using pool shock will alleviate and prevent many common pool water problems. Shocking the water helps destroy contaminants, keeping your water clear and eliminating excessive chlorine odor. It is recommended to add shock weekly, as well as before and after pool parties, after storms, and during periods of hot temperatures.
Shocking the pool will elevate the chlorine levels to kill and prevent occurrences of green, black and mustard pool algae that can discolor your water. It also eliminates bacteria buildup. A good rule of thumb is to add a pound of pool shock for every 10,000 gallons of pool water.
Algae Control
Algae can discolor both your pool water and pool surfaces like walls and ladders. This growth is usually caused by a lack of a sanitizer or by pH levels that are out of balance. It is best to balance the pH level and then add algaecide. Cleaning the pool surfaces like walls and steps and adding algaecide weekly will help to curtail any new algae growth.
Water Clarifier
Every pool owner will notice hazy pool water at some point. Whether caused by low pool sanitizer, out of balance water chemistry, a passing thunderstorm or not doing regular pool and water pump and filter upkeep, hazy water will happen occasionally. The cloudiness is due to extremely tiny dirt and debris particulate that are unable to be filtered out by the pool’s system. Pool water clarifiers will help bind these smaller together into larger particles that are easier for the filter to collect and clear from the pool. Clarifiers will also remove dirt and other contaminants that can stress chlorine levels. Clarifiers usually take about 2-3 days to complete the cleaning action.
Clarifiers work to bind particles together that will float on the water surface and be filtered out through the system. Another type of water cleaner is called flocculant, which also binds debris together but in larger parts that sink to the pool bottom and will need to be vacuumed out.
Scale, Metal and Stain Control
Using a scale, metal and stain formula for your pool will help protect against scale build up and stains from calcium, magnesium, copper, iron and other minerals and metals. This formula should be used on pool openings and closings along with spot applications during the pool year.
Pool Salt
You may not think of pool salt as a chemical but adding salt to a saltwater pool can make your water cleaner and softer to the skin than traditional chlorine pools. There are three types of salt designed for pool use: solar, mined and mechanically evaporated. Each of these is a coarse grind and should be 99% pure sodium chloride. This purity will help keep your pool from staining or damaging your pools equipment.
A salt chlorine generator (or saltwater chlorinator) takes the salt grains and converts them into chlorine, which then helps to sanitize your pool water without the higher levels associated with liquid chlorine or chlorine tablets.
There are several types of salt that contain additives that you shouldn’t use in pool water: Epsom salt, Himalayan salt and rock salt.
Pool Chemical Safety
Pool chemicals are by nature designed to manage pool water problems. They can be very harmful and hazardous to humans and animals if handled improperly. Chemicals can cause skin burns, eye damage and can be fatal if swallowed. Follow these pool chemical safety precautions:
- Keep all pool products away from children and animals.
- Wear rubber gloves and protective eyewear. Wash clothes and hands immediately after handling chemicals. If your skin comes in contact with any chemicals, flush immediately with cold water for 15 minutes and call a physician.
- Follow the manufacturer’s usage directions and safety precautions listed on the product label.
- Use clean, dry measuring equipment for chemicals. Rinse all measuring equipment after using.
- Store chemicals according to the manufacturer's instructions.
- Never return spilled material to the original container or place in the household garbage.
- Don't mix spa, pool or household chemicals together.
- Add chemicals to water. Don't add water to chemicals. Adding water to chemicals contaminates the entire container.
- Don't allow dry chlorine to become damp or wet.
- Keep open flames away from pool chemicals.
- Don't reuse empty containers. Discard any unused chemicals after closing your pool. Follow local ordinances for disposing of hazardous materials.
- Buy new chemicals when you reopen the pool.
Frequently Asked Questions
Here are answers to some frequently asked questions on pool chemicals.
Why do pools need to be treated?
Treating a pool accomplishes several particularly important tasks that make for a safe and enjoyable aquatic time. Pool treatments will ensure that your water is clear and clean and doesn’t have any harmful bacteria, viruses or algae that may cause health problems to swimmers and also damage your pool’s water system. Maintaining the balance between chlorine and pH levels in both chlorine and saltwater pools is key to having a fun day at the pool.
Why is my pool still green after treating it?
It can take several days to as long as a week for green pool algae to clear from your water. You should shock your pool every day until all of the green has disappeared and run the filter constantly until clear. Buildup from metals like copper and excess minerals can also turn water green after pool treatments. Metal, scale and stain products can help reduce and clear discolored pool water.
What chemicals do you need to treat a pool?
Here is a listing of the most commonly used pool chemicals:
- Pool chlorine to sanitize the pool water.
- Pool balancers to keep correct levels of pH and alkalinity.
- Pool shock to treat cloudy water and kill off algae.
- Pool water clarifier to help cleanse pool water of dirt and debris.
- Pool algae control to treat green, black and mustard algae.
- Pool salt for adding chlorine to saltwater pools.