A sump filter is a device used in various water systems, such as aquariums and ponds, to remove debris and impurities from water. It typically consists of a container that collects water, along with a filtration system that cleans the water before it is returned to the main body of water. This helps maintain a healthy environment for aquatic life. Sump filters can be either mechanical or biological. Mechanical filters physically trap particles, while biological filters use beneficial bacteria to break down harmful substances. Regular maintenance of a sump filter is essential to ensure its effectiveness and prolong the life of the water system it serves.