Chemicals are used to keep your swimming pool’s water clear and clean. Water, when left stagnate and untreated over long periods of time, is prone to developing bacteria, mold, and algae. A mixture of pool chemicals prevents this from happening and keep your water ready for healthy swimming. While each chemical serves a specific role, they often act in unison to perform a symphony of sanitization, as it were. However, most of these chemicals need to stay within a certain range in order to maintain their effectiveness and having one chemical “tip the scale” too far can cause others to fall out of balance as well, which may lead to unclean water. Here, we’ll show you how testing the levels of these chemicals can help you maintain the balance in your pool water. Many of these chemical levels are measure out in parts per million, or ppm. Parts per million is a common ratio in pool chemical measurement. Much like a percentage being a ratio out of 100, 1 ppm would equate to 1 pound of chemical per 1 million pounds of pool water (or 120,000 gallons of water).
Your pool sanitizer is responsible for killing the bacteria in your pool water. The three most common sanitizers on the market are chlorine, bromine, and biguanides, with chlorine being the most common. Keeping the proper level of sanitizer in your pool water prevents the growth of microscopic organisms which can lead to the outbreak of algae. Sanitizers get used up as they operate, so new sanitizer must be added on a regular basis. Chlorine comes in many different varieties such as slow-dissolving tablets, sticks, liquid or granular form. Bromine primarily comes in tablets, and biguanides primarily come in liquid form. It is important to never mix different sanitizers together (such as mixing two different types of chlorine or mixing chlorine or bromine with a biguanide), as improper mixing can lead to bad chemical reactions. Checking your sanitizer level daily is never a bad option. Once you get a sense of how much sanitizer your pool needs to maintain its proper levels, you will not need to check daily unless it is a particularly hot day or you’ve had a lot of rainfall or you have seen algae develop in your pool.
The pH of your pool water determines how acidic the water is. Keeping a balanced pH is vital to swimmer comfort, as well as the longevity of your pool equipment. On the pH scale of 1.0-14.0, your pool water should lie between 7.2 and 7.6. This range has been found to be the most comfortable for swimmers, and very close to true “neutral” on the pH scale (7.0). Test your pH level weekly and adjust its level as needed. When trying to balance pool water, use a pH increaser (sodium carbonate) when the pH is low, or acidic. Use a pH reducer (sodium bisulfate) when the pH is high, or basic/alkaline. These chemicals will keep your pool’s acidity within its healthy range.
Testing for Total Alkalinity measures the amount of alkaline material is in your pool, which affects how resistant your pool water’s pH is to change. Keeping your Total Alkalinity in balance will help keep your pH in balance. Total Alkalinity can also indicate how much scale might develop in your pool and how corrosive the water might be. The safe range for Total Alkalinity when balancing pool chemicals is 80-120 ppm. Test your Total Alkalinity weekly and adjust accordingly. Using a sodium bicarbonate-based chemical will raise your Total Alkalinity if it is low. You can lower high TA with a sodium bisulfate-based reducer. While it is true that muriatic acid can also reduce high Total Alkalinity, handling the acid can be very dangerous and messy, and therefore we recommend extreme caution if you chose to handle it.
Much like how calcium protects the bones and teeth in your body, so too does calcium protect metal in your pool from scale and corrosion. Calcium also prevents water from foaming when certain chemicals are added to the pool. Keeping a safe range of calcium in the water prevents the water from leaching calcium out of plaster in concrete pools. Increasing calcium hardness requires adding a booster, typically made up of calcium chloride crystals, to your water. Be sure to dilute the calcium crystals by pouring them into a bucket or watering can that has been pre-filled with water. Add the crystals slowly, as they tend to generate heat. Once the crystals have dissolved, add the solution to the surface of the water.
Now that you know what you’re looking for, we can go through the methods of how to test these pool chemical levels when trying to balance pool water. Test strips are a simple way to test for many pool chemicals. All it requires is dipping the test strip in the water for a period of time and then lining up the strip’s visuals (often a color coding system) with the labels to determine chemical levels. There are also digital testers that read special test strips to give you a chemical measurement. Testing can be achieved with a small sample of your pool water collected in a tube. Many test kits include a small container to collect small amounts of pool water, to which you add either testing tablets or reagents (liquid testing chemicals), which change the color of the water. Matching the changed water color to the container’s color code will indicate the chemical level. With all of these testing methods, it’s important to follow the individual testing device’s instructions. After a few tries, testing for chemical levels will become second nature, letting you easily see what is needed to keep your pool chemicals in proper balance.