*Product May Be Subject To Extended Lead Times. The UltraZap Bio Filter 5 Litre Including Bio Balls is a compact, high-efficiency biological filtration unit designed to promote a clean and healthy pond environment. Inside the filter chamber, specially-engineered bio balls provide an ideal surface area for colonies of beneficial bacteria to grow and thrive. These bacteria are essential to the nitrogen cycle, breaking down toxic ammonia into nitrite and then converting nitrite into less harmful nitrate. This natural process helps maintain water clarity and supports a stable aquatic ecosystem for fish and plants. The included bio balls enhance the filter’s efficiency by maximizing bacterial colonization and water contact, making it a reliable and low-maintenance choice for small to medium ponds. With easy installation and durable construction, it’s the perfect solution for long-term biological water treatment. Includes 80 Bio Balls Pond cap is 2500L.