Which Swimming Pool Chemicals Do I Need?

If you’re a new pool owner, the list of swimming pool chemicals and the uses for each of them can seem overwhelming. Chlorine is a given – everyone knows that a pool needs chlorine to stay clean and clear but how much? How often? What kind? And what’s this bromine stuff? It’s really not as confusing as it seems, and you don’t need a chemistry degree to understand which pool chemicals to add and when. Here are some basic tips and some information to help you understand the best and easiest way to take care of your swimming pool.

Pool Water pH and Chlorine

The main purpose of most pool chemicals is to maintain your pool water at a pH level between 6.8 and 7.2. In case you don’t remember your high school chemistry, pH is a measure of the relative alkalinity/acidity in a substance. The ideal pH balance for pool water is 7.2 – the normal pH balance for the fluid in your eyes. A pH balance of 7.0 is neutral. Below that, the water is acidic. Above that, the water is alkaline. Either one will result in problems with minerals and bacteria in the water, and in eye and skin irritation for the swimmer.

When the pH is too low, the acid in the water will begin to dissolve the surface of your swimming pool if it’s made of plaster, concrete or grouted tile. This encourages algae to grow, which results in nasty, clouded, foul pool water. The metal parts of your pool and pool equipment begin to corrode and release sulphates, which result in stains on the walls and floor of your pool. Chlorine activates too quickly when the pool water is too acidic. It doesn’t sanitize properly, and the chlorine stings your eyes, fades your clothes and dries out your skin.

When the pH is too high, the water is alkaline. Generally, it means that there is too much calcium in the water. The excess calcium will form lime scale on the walls and floor of the pool as well as in the hoses and other parts of your filter. If you’re using a sand filter, excess calcium carbonate tends to turn the sand in your filter to cement, impairing its ability to remove impurities from the water. Alkaline water affects the ability of chlorine to do its job, too – the higher the alkalinity, the less of the chlorine you put into the water will get used. At a pH of 8.0, you’d need to use five times as much chlorine to get the same effects as you would at the ideal range of 6.8 to 7.2. And again, the swimmers will deal with burning eyes, dry skin and hair that turns to straw.

Which Swimming Pool Chemicals to Use

If the pH is too low, the water is acidic. You need to add an alkali to the water to decrease the acidity. The most common alkali used as swimming pool chemicals is soda ash. Your pool maintenance store can provide you with information about how much soda ash your pool needs.

If the pH is too high, the water is alkaline. You need to add an acid to the water to increase the acidity. The two most common acidic swimming pool chemicals are muriatic acid and sodium bisulphate.

Maintaining the proper pH level in your pool will extend its life, make it more enjoyable for you and your family and save you money on other swimming pool chemicals, such as chlorine and algaecides. Make sure that you check the pH daily, and make adjustments as needed.