Final answer:
The correct answer is D) All of the above. Pools should be free from floating debris, sediment and dirt, and algae.
A pool should be free from floating debris, sediment and dirt, and algae to ensure it is clean, safe, and pleasant for swimmers.
Step-by-step explanation:
A swimming pool should be free from all of the following: floating debris, sediment and dirt, and algae. Floating debris can include things like leaves, plastic bags, and other trash, which not only look unpleasant but can also be dangerous to swimmers and can clog filtration systems. Sediment and dirt can make the pool look dirty and decrease the effectiveness of disinfectants. Algae in pools can create slippery surfaces, block filters, and affect water chemistry, potentially making it hazardous for swimmers. To maintain a healthy swimming environment, measures such as coagulation using flocculants, proper filtration, and chemical balancing are used to keep pools clean and safe for swimmers.