Final answer:
Low calcium hardness in pool water can cause corrosion of fixtures, scale formation in equipment, and difficulty balancing the pool water.
Step-by-step explanation:
Low calcium hardness in pool water can cause a range of issues. It can lead to corrosion of pool fixtures, such as metal rails and ladders, due to the aggressive nature of the water. Additionally, low calcium levels can cause the formation of scale in pool equipment, such as pipes and filters, which can restrict water flow and reduce equipment efficiency. Finally, maintaining appropriate calcium hardness in the pool water helps to balance the overall chemistry of the water, preventing other imbalances that can cause problems.