There are some basic steps you will want to take concerning your swimming pool water to enjoy your pool to the fullest. Pool water problems can be frustrating, and makes the pool more of a headache, not the enjoyment it was meant to be. Allow me to give you some of the basic pool water chemistry information to help keep your pool an enjoyable experience.
Chlorine is the primary sanitizer for many pool owners. To keep water clear and continuously kill bacteria, keep the chlorine level above 1.0 ppm (parts per million). There are many ways to accomplish this, but unless you have a salt chlorine generator, you are probably using chlorine tablets to maintain your everyday chlorine level. You can also use granular or liquid chlorine (bleach) to establish the chlorine residual, but slow-dissolve tablets are more economical to use for everyday pool sanitation. I personally use the 3” tablets to keep my chlorine level constant, and use granular chlorine as a periodic shock treatment. Chlorine tablets are a slow dissolving type of chlorine; use 1 tab per 5,000 gallons per week. The best way to use these tablets is with a chemical feeder or chlorinator.
Stabilizing the pool water; this is done with a Cyanuric Acid, a product sold under the name of pool conditioner or stabilizer. It "Stabilizes" the chlorine molecule, making it less susceptible to sunlight degradation. The range for pool stabilizer is 40-80ppm. maintaining at least 40 ppm on the stabilizer level will makes the chlorine last longer in the water, reducing your chlorine usage by 50% or more. After you add stabilizer to the water to the proper level, the Cyanuric will stay in the water, and you only need to replace what is lost to backwashing or splashout. Typically 1 to 3 doses of stabilizer are added per year, to maintain the level above 40ppm.
Our next step is the Total Alkalinity; a measurement of the carbonates and bicarbonates in your pool water. For Alkalinity, the level should be between 80 to 120 ppm. If your pool is painted, you should maintain a level of 150ppm, to protect the paint. To raise the alkalinity level, use products labeled alkalinity increaser or alkalinity plus. Keeping the alkalinity in range will allow you to adjust the pH more easily and it helps maintain proper pH levels by allowing the water to neutralize acids and bases, preventing swings in the pH level. In this way, your Alkalinity level "buffers" your pH level.
Speaking of pH - this is a measure of how acidic or basic your pool water is. Everything has a pH value and some relative level of acidity or basicity, unless . Our blood and our eyes are right around 7.4 on the pH scale. Is it coincidence that 7.4 is the optimum pH level to have in your pool? And not just for swimmer comfort, but having a pH in the range of 7.4-7.6 allow our chlorine to work more effectively. Proper pH levels will also protect your pool surfaces. pH that is too high is scaling and pH that is too low is corrosive to our pool surfaces. To adjust the PH, either up or down, you would add products labeled pH plus or pH minus. These are bases and acids, respectively, that you add directly to the pool water to make the pH slightly more acidic (lowering the pH) or slightly more basic (raising the pH).
Calcium Hardness - a measure of how hard or soft your water is. The proper level for calcium hardness is 180 to 220 ppm, but some pool experts will say 200-400 is acceptable. Vinyl liner pools can run on the low side, but for plaster pools, having a low calcium hardness level could lead your water to become aggressive and seek out calcium, which it finds in your pool plaster or tile grout. Over time, this can etch pool plaster. On the opposite end of the scale, if your calcium level is too high, as it will be in many parts of the country with hard water, you may find calcium deposits or efflorescence to be a problem, or the calcium may frequently come out of solution, clouding the pool water. High calcium levels will also clog up salt generator cells fairly quickly. To raise the level of calcium hardness in a pool, you can use calcium carbonate, generally labeled as calcium hardness increaser. If your calcium hardness level is too high, the common solution is to "lower by dilution", which means to drain out some water and refill with water that has a lower calcium level. There are some sequestrants available that can be used to lock up calcium.
Pool Water Testing Check List
It is the title of the post, after all - so I feel obligated to provide a checklist for pool chemistry. It's purposely devoid of too much detail, to show you the minimum, basic requirements to maintaining your pool water balance. Right-click the image to print it out and post on the fridge as a reminder.
With the exception of filtration or circulation problems, all the woes befalling a pool owner can be attributed to water balance. If you keep these 5 levels in the good range by regularly testing and adjusting as needed, you will enjoy sparkling and trouble free pool water.
SPP Pool Expert