A pond filter is a device used to clean and maintain the water quality in a pond. It removes debris, algae, and harmful substances, ensuring a healthy environment for fish and plants. Filters can be mechanical, biological, or chemical, each serving a specific purpose in the filtration process. Using a pond filter helps prevent issues like murky water and unpleasant odors. Regular maintenance, such as cleaning or replacing filter media, is essential for optimal performance. By keeping the water clear and balanced, a pond filter contributes to the overall health and beauty of the pond ecosystem.