Kintama is a new bio filter media with an incredible capacity for holding beneficial bacteria. This helps prevent growth of algae and helps stabilize PH levels. This high level of bacterial mass can also rapidly reduce harmful ammonia and nitrite levels. Easily one of the best medias currently on the market. Suitable for all types of aquatic installations, aquariums, ponds & marine. These balls vary from approx 20mm-22mm in diameter. Available in: Kintama Gold Bio Balls 10lt (approx 5kg) Kintama Gold Bio Balls 25lt (Approx 12.5kg) Kintama Gold Bio Balls 20kg