Calcium is dangerous for your swimming if you have too much! When it comes to calcium hardness in tap water there are certain places in the country that have much more than others. In those places, the calcium coming out of the tap water is higher than what is recommended for a swimming pool but it’s important to note that swimming pools need a certain amount of calcium to keep the interior finish intact but there are issues when it gets too high. For swimming pools, the standard and recommended amount of calcium hardness are between 200 – 400 parts per million (ppm) but in certain areas of the country, the calcium hardness coming out of the tap is 400ppm and higher! The challenges for residential and commercial swimming pool owners is when calcium levels get too high in their swimming pool. When these levels continue to climb scaling occurs on the water tile line, the interior finish, filtration equipment, decorative water features, and spillways. It can also be challenging to manage the water chemistry too! If you happen to have a saltwater chlorinator, high levels of calcium hardness will prevent it from functioning properly.
So what happens when calcium levels get too high? The simple answer is it must be removed/lowered from the swimming pool water. At this point you can choose to drain and refill your swimming pool which takes 2-3 days, can damage your interior finish and you will be filling it back up with your cities hard water.