Pool Chemistry 101

Operating a swimming pool isn't nearly as difficult as some people believe as long as you understand the different swimming pool chemicals involved and what job each of them performs. Below we will go over the chemicals used for swimming pools and explain how they work.

Free Chlorine Free chlorine is basically a sanitizer which is used to keep the water clean and safe. However, chlorine levels need to be replenished constantly to be effective. The quickest method of raising the chlorine level is by using liquid Chlorine. The best way to add bleach or liquid chlorine to a pool is to pour it in front of one of the return jets slowly when the pump is operating. You should then keep the pool running for at least an hour to let the chemical circulate through the water. Its important the free chlorine level is maintained to keep the water properly balanced. You don't want too little or too much chlorine in the pool. If the chlorine level drops there's a good chance you'll get algae in the pool and the water will become unsafe. The best way to check the chlorine level is a simple pool testing kit. It's a good idea to test the chlorine level every day or two and add chlorine when needed.

PH - Acidity/Alkalinity

To maintain proper pool care, the pH level of the water should be kept between 7.2 and 7.8 to protect your equipment and prevent irritation. If the pH is too high, you can lower it using muriatic acid (which is inexpensive and works well with saltwater chlorine generators) or dry acid (which is easier to handle and commonly used by pool owners without generators). Muriatic acid comes in varying strengths, and when using it, pour it in front of a return jet with the pump running and let it circulate for an hour. Dry acid, sold under names like pH Reducer or pH Down, should be dissolved in water and added slowly to the pool. Regular pH testing is important, as levels between 7.2 and 8.0 are generally acceptable for swimming. If the pH drops below 7.2, the water may irritate eyes, and below 6.8, it could damage pool equipment. If the pH is above 7.8, calcium scaling may occur. To raise the pH, use soda ash or borax, which are available under names like pH Up or pH Increaser.

Total Alkalinity

Total alkalinity helps to keep the PH in proper balance and it also needs to be tested on a regular basis. Too much alkalinity can cause the PH level to rise and you'll need more chemicals to alter it. A common way to raise the total alkalinity is by spreading baking soda across the water in the pool's deep end. If the total alkalinity needs to be lowered, make sure the PH is between 7.0 and 7.2 by adding acid to lower it as this will also lower the alkalinity.

Calcium Hardness

Calcium hardness will let you know how much calcium is in the water. Pools with vinyl liners don't require calcium while plaster pools without salt-water chlorine generators should have a calcium level from 250 to 350. If the pool has a generator, the level should be from 350 to 450. The calcium level can be increased with calcium chloride while the level can be lowered by replacing the water or by reverse osmosis water treatment. The proper level of calcium will help prevent damage to the plaster since high levels can lead to calcium scaling. Many pool shops sell calcium chloride under names such as Hardness Plus and Calcium Hardness Increaser. The best way to add it is to spread it in the pool's deep end.

Cyanuric Acid

Cyanuric acid is also known as conditioner or stabilizer and it protects the free chlorine from sunlight as well as determining the proper free chlorine level. When the Cyanuric acid level is higher it means you need more fee chlorine. The best level is typically from 30 to 50 if you don't have a salt-water chlorine generator and from 70 to 80 if you do have a generator. Cyanuric acid is available in both liquid and solid form with the liquid being more expensive. It usually takes about a week for solid stabilizer to show up on your test kit so you won't need to re-test for it until a week after it's been added. You can add solid stabilizer by placing it in the skimmer basket and running the pump for 24 hours. However, the stabilizer should be placed in a sock ad after it's added you shouldn't clean or backwash the filter for a week. If the acid needs to be lowered, the best way is to replace the water or via reverse osmosis water treatment.

Salt

Salt is needed if you have a saltwater chlorine generator and it should be at least 99.4 percent pure. The salt level can be raised with water softener salt crystals or pellets which don't have any additives and/or rust inhibitors. Pool salt can also be used but is costlier. Just be sure you don't use deicing salt, rock salt and/or table salt. Feel free to simply pour the salt into the pool and spread it around if possible and run the pump for 24 hours. If you have a saltwater chlorine generator you should turn it off when the salt is added and leave it off for 24 hours.

Borates

Borates are considered as an optional way to control the PH level and fight off algae and the recommended level is from 30 to 50 ppm. The level can be increased with muriatic acid and boric or boric acid. For more information on pool chemicals please feel free to contact us at Discount Pool Supply, we offer fast and free shipping across Canada and carry all of the pool chemicals you need to keep your pool crystal clear all season long.