Newa Aqua Bioglobe, uniquely shaped beads made from isostatic polypropylene helping develop bacterial colonies. Furthermore this unique design offers excellent mechanical and thermal resistance. The beads offer a large surface area which can sustain a multitude of bacterial colonies, the bead diameter can switch from 32mm to 20mm to prevent any hindrance in water flow. This also provides the nitrifying bacteria with optimal oxygenation providing the best possible aquarium conditions. The practical, re-sealable and waterproof container keeps the product fresh and free from impurities. Feature: 1 Litre tub (35 Pieces) treats max 60 litres. 22mm in size, expanding to up to 32mm. Suitable For: Freshwater. Marine. Reef.