Power Sand Special will be switched to POWER SAND ADVANCE. This product has more nutrients than POWER SAND BASIC, and on top of Bacter 100 and Clear Super, it contains BC powder (bamboo charcoal powder), which helps encourage the growth of plants. Choose an appropriate granule size (Small, Medium, Large) based on depth of aquarium water in your tank. 2-liter and 6-liter bags are available.