A circular 25cm diameter air diffuser disc designed for koi ponds and aquariums. Produces a fine, even curtain of micro-bubbles that maximises oxygen transfer efficiency — essential for healthy fish and a balanced aquatic environment. Oxygen is fundamental to fish health, beneficial bacterial activity in your filter, and the overall biological balance of any aquatic system. A high-quality diffuser distributes air evenly across its entire surface, producing smaller bubbles than cheaper alternatives — and smaller bubbles mean more surface area, more oxygen transfer, and less turbulence. Key Features: • 25cm diameter — suitable for medium to large ponds and aquariums • Fine-bubble diffuser membrane for efficient oxygen transfer • Even bubble distribution across the full disc surface • Weighted base keeps the diffuser on the pond or tank floor • Connect to any standard aquarium or pond air pump via airline tubing • Durable construction for outdoor pond use 📋 How to use: For best results, position the diffuser at the deepest point of your pond. Multiple diffusers can be run from a single pump for larger installations. Free Delivery