How to Test and Adjust Calcium Hardness

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  • 1-2 hours
  • Beginner
  • 40-100

Testing calcium harness involves a simple three-step process. All you need is a Taylor kit. If you don’t regularly test the calcium harness, pitting or scaling may develop. Also, testing can reveal such issues as pool leaks. Below are the three basic steps to doing this calcium hardness testing, as well as how to interpret results.

Calcium hardness testing is what’s referred to as a “titration” type of test, and includes the following three elements:

Step One: Add a Buffer solution.

The first thing you’re going to need to do, in order to test calcium hardness, will be to add the buffer solution to the sample. If, for instance, you’re using the Taylor test kit, this buffer solution portion is accomplished by putting in 20 drops of R-0010.

Step Two: Add calcium hardness test solution.

After you have applied a buffer solution, you’ll next need to put in some calcium hardness test solution along with the sample. For Taylor test kits, this step is accomplished by mixing in 5 drops of R-0011 and swirling it a bit. However, if the water is a little on the chilly side, it may take some extra manual agitation to cause this solution to completely dissolve.

Step Three: Add test reagent.

Now you’re ready to mix in a test reagent along with this sample. This you must do drop-by-drop, by counting the number of drops until the test sample begins to change color. This process is called “titrating” the sample. In Taylor test kits, you will mix in R-0012 one drop at a time until the sample changes from a blue tint to a red tint. Once you have counted the R-0012 drops added, multiply these by ten to come up with the final alkalinity reading. Therefore, if you need 25 drops, your reading will be 250 ppm.

Step Four – interpret your test.

Be sure to keep calcium hardness somewhere within the 250 to 500 range, which wards off pitting and scaling. If calcium hardness goes too low, it might become water-starved and such calcium from the plaster, which then leads to pitting. However, if calcium hardness goes too high, it might begin to see some scaling or cloudiness. Therefore, if you keep your alkalinity and pH lower, the effect of any higher calcium hardness can be mitigated. For the most part, scaling issues happen right after a pool has been re-plastered, which is caused by dust that sticks to the surface.

Please note that low calcium hardness readings may reveal that your pool is losing much water. Generally speaking, calcium harness should remain relatively consistent in the pool, which means it is not sacrificed via evaporation. Therefore, if it begins to drop consistently, you might have a leak someplace in your pool.

Nobody wants scaling, pitting, or leaks to get in the way of enjoying a pool. Therefore, it’s in your best interest to learn how to test calcium hardness and make such testing a regular pool maintenance task. The above 1, 2, 3 procedure makes it easy for anybody to fit this task into their routine.