ITEM NAME:36pcs CO2 Tablet Carbon Dioxide For Aquarium Fish Tank Plants Diffuser3cT Fertilizer types: basal Sizeï ¼Å¡10x 3x 6.5cm Package included ï ¼Å¡1 boxs/36pcs x Aquarium CO2 Tablet Features: This product adopts the latest formula, no poison, no pollution, no    suspension agents, tablets slowly toward the water releasing carbon   dioxide, provide the right amount of carbon dioxide to aquatic plants,   absolutely does not affect the fish growth. Method of use: Different parts in the tank. (the best use of the proposed methods is  the CO2 into the filter used together) Usage: every 40 liters of water into the 2 slices, add 2 times a week. Noticeï ¼Å¡ 1.Please allow 1-3cm error due to manual measurement.Pls make  sure you do not mind before you.Different parts in the tank. The color may have different as the difference display,pls understand.