Celebrating Calcium

Back in the 1980’s and 1990’s, there was a popular commercial advertising milk. It used the tagline, “Milk. It does a body good!”  It emphasized that milk builds strong bones and muscles, promoting health benefits that are derived from calcium. This included promoting strong bones and teeth. Calcium is also important for pools. Calcium is needed in pools to maintain the structural integrity preventing corrosive water from damaging equipment and surfaces.

Calcium Hardness

Calcium hardness is the calcium portion of the total hardness of the pool. It is important to help protect the pool and equipment from natural corrosion. We have all heard of water being soft (low calcium) or hard (high calcium). In places where calcium is too hard, people install water softeners to help combat high calcium levels. Calcium tends to be naturally present in water due to leaching that occurs when the water comes in contact with the contents in the earth that dissolve into our water. When we need to add calcium to our pools, we use calcium chloride. Testing the fill water is a good idea so you know what type of water you have. If you use the fill water from your garden hose to fill your pool, this will let you know whether you are starting out with pool water with high or low calcium levels. This will give us the information we need to treat and maintain your calcium level.

Low Calcium

If the calcium level is too low (soft), the water will become aggressive and seek calcium elsewhere. This calcium can be found in plaster and gunite surfaces and in grout. While low calcium levels do not affect vinyl liners as severely as they do plaster and gunite surfaces, you still do not want to have low levels as it leads to foaming (more common in spas), flakes, heater failure, and itchy skin. Ideally you want to maintain your calcium hardness levels between 200-400 for pools and spas and vinyl liner pools between 150-250 ppm.

High Calcium

When you have high calcium (hard), there is too much calcium in the water which can lead to rough pool/spa surfaces, clogged filters, cloudy water, clogged heater elements, reduced circulation, and eye and skin irritation. High calcium levels can be lowered with the addition of fresh water, assuming that the water has a low calcium hardness. If the fill water has a high calcium hardness level, you may want to consider installing a softener. With spas, it is often recommended to drain and replace the water. This is because calcium is not very soluble and at higher temperatures it is even less soluble.

Calcium Hypochlorite

While not a factor of calcium hardness, calcium hypochlorite can affect your hardness level. Calcium hypochlorite is a form of chlorine. It comes in granular, brickette, and tablet forms. If you are using this form of chlorine as your main sanitizer or as a shock, be aware this can minimally increase your calcium hardness levels as it does contain calcium.

Calcium Care

If you want the fill water tested, there are kits available or we can run a test when we are at your pool. If you are using calcium hypochlorite and want to switch to a different form of sanitizer, let us know. This can help to develop a plan for your pool to keep it strong!