Only add calcium chloride when the pool is full. The heat from it can damage the pool finish if you add it while the pool is still filling. Wait one full cycle before retesting the water, and adjust the chemical levels if needed.
Add drops of reagent R0012 to the water and count the drops, each drop has a value of 10 parts per million (ppm). Stop using reagent R0012 when the water turns blue. At this point, you can take the number of drops and multiply it by 10 to get your parts per million calcium hardness.
The best ways to remove calcium carbonate is to use a calcium releaser/cleaner, preferably an acid-free product, so it doesn't ruin the finish of the pool tile or glass. Next, you can try using a pumice stone or scale remover.
Among the different pool levels you need to maintain, you can't ignore calcium hardness. Calcium hardness details how much calcium is present in your pool water. It may come as a surprise, but calcium plays an important balancing role. Failure to keep water hardness in check can cause permanent damage to your pool.
Low Calcium Levels in the Pool
Low calcium, as is often the case, will cause long-term serious damage especially to plaster, vinyl liners, grout in between tiles, metal rails, and even concrete decking around the pool. Here's why it happens. Plain old water, believe it or not, is very aggressive.
A low hardness level can lead to corrosion of the pool surface, filter, heater, ladder, etc. Likewise, if the water is too soft(low calcium level) you are also more likely to experience problems with algae. A calcium hardness level that is too high can cause cloudy water and scaling (a white chalky appearance).
Calcium hardness is also very important to the chemical balancing of your vinyl liner swimming pool. Calcium for a liner pool can be a bit lower than a plaster pool, in the range of 150-250 ppm.
A good rule of thumb is to never mix pool chemicals with each other. After adding Calcium Hypochlorite a user should always wait 24 hours before adding chemicals that would alter their pH. Adjusting pH or Total Alkalinty after adding Calcium Hypochlorite can cause the calcium to temporarily cloud the water.
Most balancing chemicals, such as pH, alkalinity, and calcium hardness, will become incorporated into the water within an hour of adding them, at which time swimming is safe. Shock takes longer to adjust with the pool water, so waiting overnight after shocking before you swim is recommended.
Alkalinity and Calcium Hardness in Daily Operations
Optimal range for alkalinity is roughly between 60-120 ppm. Just remember, the higher you go, the harder time you will have affecting change on your pH, in either direction. Calcium hardness should be kept at 250 ppm minimum.
However, adding too much baking soda might also raise the PH level of your pool to an undesired stage (alkaline). In the case where too much baking soda is added to hard water, it can cause a build-up of calcium around your pool.
What causes excess calcium in a swimming pool? In most cases, excess calcium happens when your pool water is not properly balanced. Common culprits are high pH, fluctuating temperatures, and evaporation.
It's usually just a temporary reaction as the sanitizer works its magic, and doesn't always indicate a problem. But if the cloudy water persists long after you've shocked the pool, you're likely having an issue with water balance, circulation, or filtration.
Once the pool water's alkalinity level rises, the pool becomes a breeding ground for algae and cause calcium buildup–both of which greatly affect water clarity.
Cloudy water may still be safe to swim in, but if the chemicals are not balanced, then swimmers can experience red eyes, irritated skin, and rashes. If the cause is environmental factors, it can usually be cleared up with a clarifier and regular cleaning.
Baking soda, also known as sodium bicarbonate is naturally alkaline, with a pH of 8. When you add baking soda to your pool water, you will raise both the pH and the alkalinity, improving stability and clarity. Many commercial pool products for raising alkalinity utilize baking soda as their main active ingredient.
Too-soft water will be corrosive to your pool. It can dissolve concrete and plaster, and corrode any metal parts submerged in or touched by the water. It all amounts to expensive repairs if you don't bring the calcium hardness level back up.
Calcium hardness.
For vinyl pools, calcium should be between 150-250 ppm. A low level can result in foaming, which is unpleasant but shouldn't harm the liner. If calcium hardness goes above 400 ppm, you will likely see a white, flaky crust on the liner and pool equipment.
Hardness is the sum of the multivalent metal ions in solution, whereas alkalinity is a measure of the solution's ability to neutralize acids (sum of hydroxide, carbonate, and bicarbonates). In natural water systems calcium carbonate is usually present and responsible for different characteristics of the water.
Excessive levels of pool chemicals can cause your water to become cloudy. High pH, high alkalinity, high chlorine or other sanitisers, and high calcium hardness are all common culprits.
If, for example, you add too much of a calcium supplement, you will drive down alkalinity as you get precipitation of calcium carbonate in the tank. Likewise, adding too much of an alkalinity supplement can result in reduction of calcium.
It will slightly raise your pH, so make sure you adjust pH while using it. As the name implies, it will also raise your calcium hardness levels in your pool slightly. It is sold in granular or in pucks/tablets.