Baking soda will not soften (remove calcium hardness) from pool water. It will raise total alkalinity.
calcium
Presence of bicarbonates of chlorides or sulphates of calcium or magnesium in water are the main causes of hardness of water.
If the calcium is a result of pool chemicals, draining some or all of the pool water will lower the calcium hardness level. If the cause is the fill water, commercial hardness reducers or chelating agents will bond with the calcium to keep it trapped in solution.
The hardness of bone is due to the calcium salts deposited in it.The exceptional hardness of bone, which allows it to resist compression, is attributed to the presence of inorganic hydroxyapatites. Hydroxyapatites such as calcium phosphates are particularly important for bone hardness. Organic substances such as collagen fibers contribute to tensile strength, but not to hardness.the presence of inorganic hydroxyapatites.
calcium and magnesium
Buildup of minerals like calcium.
Hardness increaser from your pool supply company
The function of calcium salts is to provide hardness and strength and resist compression.
calcium-phosphate salt crystals
The calcium reacts with the water, producing calcium hydroxide and hydrogen gas. Ca+ 2H2O --> Ca(OH)2 + H2
The recommended frequency for checking calcium hardness in swimming pools is once a month. Other water tests will depend on how often the pool is used.