Yes, an inground swimming pool can become a still-water pond for fish with proper planning. First, drain and clean the pool, inspect for leaks, and consider adding a pond liner. Next, create varied depths, introduce aquatic plants, and establish a safe water source.
Choose fish species suited to your climate and avoid overstocking. Ongoing maintenance includes monitoring water quality, feeding appropriately, cleaning debris, and winterizing in cold climates. Always check local regulations before starting.