ITEM NAME:Co2 Indicator Solution Glass Drop Checker Replacement Solution for Aquarium 15ml Description: Aquarium CO2 Monitor Carbon Dioxide Glass Drop Checker with 15 ml Monitor Fluid. Different color of liquid represents different concentration of CO2. BLUE means that CO2's concentration is too low. GREEN means it is normal. YELLOW means that CO2's concentration is too high, excessive CO2 may cause and shrimp to die of oxygen deficiency. Concealed glass groove is easy to open and fill into liquid. Packaged with monitor liquids, which can be directly dropped into and use. Specification: Material: Glass Liquid: 15ml Suitable For: Long-term CO2 monitoring Size: 115x115x40mm / 4.53x4.53x1.57inch Package Includes: 1 x Glass CO2 Monitor 1 x 15ml Monitor Liquid SKU: ALU0003754364029932.Aquarium CO2 Monitor Carbon Dioxide Glass Drop Checker with 15 ml Monitor Fluid. Liquid: 15ml. 1 x 15ml Monitor Liquid. Different color of liquid represents different concentration of CO2. 1 x Glass CO2 Monitor.