Efficient Filter Technology: ① Coarse Blue Sponges: Designed for filtering large particles, the blue sponge uses large pores to isolate and filter large contaminants. It also promotes the activity of nitrifying bacteria for efficient degradation. ② Fine Yellow Sponges: Designed for filtering small particles, the yellow sponge uses small pores to isolate and filter fine contaminants. Easy Maintenance: Simplify your pond care routine with our biological sponge filters that are easy to clean and replace. The blue and yellow sponges effectively capture small and large contaminants to ensure a pristine pond environment. [All-Year Reliability] - The sponge sets are designed to withstand a variety of weather conditions and provide consistent pond filter performance throughout the season. Trust in their reliability, whether it's scorching summers or freezing winters. Complete Pond Care Solution: Say goodbye to cloudy water and enjoy a pristine pond. Each model is tailored to the size of your