Calcium hardness or CH for short, is the measure of the amount of dissolved calcium content present in your pool water. Calcium as we know it is a mineral that is naturally present in water and it is usually found in high concentrated levels. Whenever your pool or spa has high concentrations of calcium present, you have what is called hard water. On the other hand when the calcium level is low, you will have what we call soft water. to properly manage your pool water chemistry, you must remember that total hardness and calcium hardness in a spa or pool are different; although, they are related entities.
Total hardness is the sum of calcium, magnesium, iron, manganese, and other elements found in your water facility. It is usually expressed in grains of hardness (i.e. 1 grain = 17.1 ppm).The calcium hardness in swimming pools and spa water systems is ordinarily measured as calcium carbonate. However it is not in solution, calcium carbonate is exhibited in your pool and spa as scale. This is a white scale formation that is also a type of natural salt. This scale like salt can be found in nature in the form of one of the following
- Chalk.
- Calcite (check spelling).
- Aragonite.
- Limestone.
Calcium carbonate is not very soluble in water and unless your pool water chemistry is properly maintained, it can drop out of solution very easily. Another concerned behavior that pool owners and operators have with calcium, is that unlike most other pool chemicals, it becomes less soluble as the temperature goes up. Because of this basic understanding, proper management of hot water systems become more perplexed.
In order for you to maintain proper water chemistry in your swimming pools, your calcium hardness level should always be in the range of 200 to 400 ppm. If the level of the hardness in your calcium content rises above 400 ppm, you must take extreme measures to maintain your total alkalinity and pH at lower levels. This is a precaution that will help you avoid any scale formation in your pool and spa. This is an absolute must if the water in your aquatic facility is heated. You will be faced with an impossible task of maintaining your pool or spa water balance, if your Calcium level reaches 1000 ppm.
When your calcium hardness is too low!
Whenever the CH level in your swimming pool or spa is too low, the water in your facility will become very aggressive or very corrosive. Low levels of calcium is also a major contributor to foaming in spas or hot tubs. This is a pool water problem that is not good for the plaster or concrete surfaces in your pool or spa. The truth of the matter is that you should test the calcium content in your water regularly and if it is too low, take the necessary steps to correct it at once. Failure to take action, will result in your water having the capacity to leech or dissolve calcium carbonate from your pool and spa surfaces.
Pool and spa water that is corrosive, will lead to some very costly damages to their surfaces. Some of the problems that can occur are as follows:
- Etching or pitting of your pool and spa surfaces. This water problem can occur in a very short time period if you fail to monitor your pool water chemistry.
- Staining of your pool or spa surface walls.
- Failure of your pool or spa heating system.
Raising your CH levels
It is reported that low levels of CH or soft water is a major hk pools contributor to a lot of surface damage to pools and spas around the country. So once you have done a calcium hardness test and determined that you have to take immediate steps to raise it, the required pool chemicals must be added. The recommended pool chemical of choice for this task is calcium chloride. This pool chemical comes in two different forms which are sold at different strength as well.
- Hydrated Chloride is the first of the two that we will mentioned. This pool chemical can be purchase at 77% strength.
- The next one is the anhydrous calcium chloride. This is one of the two pool chemicals that you can get at full strength if you so desire. It is sold at 100% full strength.
It does not matter which of these two pool chemicals you choose, just remember to read the manufacturer warning and instructional labels. This is for your safety because both of these calcium chlorides can generate a significant amount of heat when they are added to water. For this reason a good practice to get into is, to dissolve either one of these pool chemicals in a bucket of water and thoroughly mix them prior to slowly adding them to your pool and spa.