The Best Way to Test Your Inground Pool Water

Clean, balanced pool water is essential for a pleasant swim. Proper maintenance requires diligent attention to filters, pumps, and especially the chemistry of your pool water. For a safe and enjoyable swim, owners must test their pool water for six essential components.

The pH is the single most important element in swimming pool water chemistry, as it affects every other chemical balance in pool water. pH is the measure of acid vs. base of a solution. The pH scale runs from 0 to 14 with 7.0 being the neutral point. It is important to maintain a pH reading between 7.4 and 7.6, ideally at 7.4, to ensure swimmer comfort, water balance and to maximize the effectiveness of your sanitizer. The type of sanitizer you use can affect your pH as will rain water and many other things, requiring you to test and adjust your pH on a regular basis.

The next parameter is Total Alkalinity (TA.) This is a measurement of the concentration of alkaline minerals in your pool water that provide a pH buffering capacity (the water’s ability to resist sudden changes in the pH). Although Total Alkalinity is not the same as pH, it is instrumental in stabilizing the pH to prevent fluctuation. The ideal range to maintain your TA is 100-150 ppm (Parts per Million, unit of measure.)

The softness or hardness of your water is measured by the calcium levels in your pool. Calcium Hardness is a measurement of calcium and magnesium in your water. Water hardness levels can vary quite a bit depending on what part of the country you live in. Having the proper level of calcium hardness is important to maintain water balance. If the level is too low, the water can be corrosive and plaster surfaces can begin to etch. If too high, staining, scaling and cloudy water can appear. Ideal range for traditional white plaster is between 200 and 350 ppm, swimming pools with an exposed aggregate or ansybrite finish have an ideal range of 157 to 250 ppm.

The most common disinfectant is chlorine. Free Chlorine (available) is the measure of chlorine’s active disinfecting power. There are several forms of chlorine available today — granular, tablets, liquid, etc. Each may have a distinct advantage in ease of application, however, once they are in the pool they all do the same thing — sanitize, disinfect and oxidize your water. Organic material, bacteria and algae are regularly introduced into the swimming pool water, yet are not always visible to the naked eye. That is why it is important to maintain a Free Chlorine residual of 1–3 ppm to keep your water free of these micro-organisms.

Total Chlorine is a measurement of both the Free Chlorine (available) and the Combined Chlorine (chloramines) in your pool. As mentioned earlier, Free Chlorine is the active sanitizer available to disinfect your water. Combined Chlorine is formed when chlorine combines with organic compounds to form chloramines. This “used,” or Combined Chlorine, has already done its job and needs to be removed from the water or it can cause skin and eye irritation and the “chlorine-odor” that is often associated with too much chlorine in the pool. Actually at that point the pool needs more chlorine, not less. It is the Free Chlorine that needs to be increased. This is achieved by shocking or super chlorination. For questions on shocking or super chlorination please contact a pool professional.

Cyanuric Acid, also known as conditioner or stabilizer, shields chlorine from the sun, reducing chlorine consumption by up to 50{1b1ead7f491439c25739d151ffbe191d851c0b7a2d88cd70f9532c1b95ba4fbe}. Some chlorine products are stabilized, such as dichlor and trichlor chlorine products (contain cyanuric acid). Granular chlorine (calcium hypochlorite) and liquid chlorine (sodium hypochlorite) are not stabilized. Once added to the water, cyanuric acid does not leave the water. The levels can be lowered by rain or make-up water and raised by the use of stabilized chlorines. You should have your water tested for cyanuric acid levels by your pool dealer on a regular basis to maintain a 30-50 ppm reading; pools using salt generators should maintain a level of 40-75 ppm.

The Total dissolved solids (TDS) level is important but not one of the 6 crucial parameters that need to be tested on a regular basis. TDS is the measurement of natural and other sources of organic and inorganic matter found in swimming pool water, water treatment chemicals, lotions, vegetation etc. The ideal range for the TDS is 1,500 to 3,000 ppm, above startup levels. When levels start reaching maximum recommended levels the water becomes over saturated. A saltwater pool will be in the higher range of TDS to start out as salt itself has high TDS. Consult a pool professional on the proper way to reduce levels when they start to climb out of the acceptable ranges.

Now that you have the basics, below are some of the different options for testing your swimming pool water.

To make testing your pool water easier, we have some great products for you to see. Shop online for all your pool supply needs and learn more about our most popular pool testing kits.

Test Strips

Water testing strips “dip-n-read” are one of the easiest and most convenient ways to monitor the water balance of your pool. Just dip one test strip in your pool for the results. Tests strips come in a variety of different options, choose the one that best suits your needs. Test strips are a good option for quick results that will give you a general idea of the pool balance. We still recommend that your water should be tested by a professional at least once a month.

Residential Reagent Test kits

Testing kits containing liquid reagents will also have a wide range of different options to choose from. The kits range from basic testing (chlorine and pH) to including all six parameters. These test kits include liquid reagents, color wheels, testing vials and DPD tablets. The liquid reagent kits are a little more time consuming than using the test strips but will give you a more specific reading. Testing results are obtained by adding a specific amount of pool water to a vial then adding the liquid reagent to the vial. As you add the reagent you will count the amount of drops it takes to change the color depending on what you are testing for (pH, TA, TC etc.) then multiply the drops to get the results. When choosing your pool test kit make sure the instructions are included with charts to find adjustment amounts.

Salinity Testers

For owners with salt-water pools, Aquachek has two options to choose from. A digital salinity tester or salinity test strips to test the levels of salt in the water. Too much salt can be irritating for swimmers, while not enough salt will create unclean water. Use this device for a quick reading and get your levels back in a safe range.

Shop for All Your Pool Testing Kits with Anthony and Sylvan

Find all the pool maintenance products online with Anthony and Sylvan’s Pool Supplies. Shop for all the pool testing kits you need to make sure your pool water is clean and ready for a daytime or nighttime swim. Visit us online to learn more about all your pool maintenance needs. For any questions, give us a call at (888) 253-SWIM.