This test solution offers efficient measurement and precise display of CO2 concentration, allowing you to make informed decisions regarding the carbon dioxide supply in your aquarium. By regularly monitoring the CO2 levels, you can ensure that your aquatic plants receive the necessary nutrients for their growth and development. Features -Color:Multi -Material:methyl blue -Size:7.70X2.10X2.10cm/3.03X0.83X0.83in -Note: 15ml, no need to mix with tank water; Green: right balance of CO2; yellow: too much CO2; blue: too little CO2 -Ensure thriving aquatic plants by maintaining optimal levels of co2 in the aquarium. -Make well-informed decisions about co2 concentration with the precise display provided by the co2 detection liquid. -Enjoy user-friendly operation that caters to the needs of all aquarium enthusiasts. -Experience the versatility of this product, which can be used in various aquarium settings. -With reliable measurements, this testing indicator solution helps maintain optimal water conditions for aquatic , very useful. Package list: 1 x bottle of indicator solution