【Essential Aquarium Accessory】Maintaining an appropriate carbon dioxide (CO2) concentration in an aquarium is one of the key factors for the health of an aquarium ecosystem. With the help of an aquarium CO2 meter, you can easily monitor the CO2 levels in your aquarium at any time, helping your fish and aquatic plants grow healthily. 【High-Quality Materials】The aquarium CO2 meter is made of non-toxic transparent glass, making it safe and durable. The transparent material allows you to clearly observe changes in the water's color, thereby understanding the CO2 content. 【Powerful Suction Cup Design】The aquarium CO2 meter features a suction cup design, making installation and removal very convenient. Simply install the product on the inner wall of the aquarium, 5-10 cm above the water surface, for long-term use. 【Easy CO2 Detection】The glass drop-type CO2 meter is very easy to use. You only need to observe the color of the liquid to understand the CO2 content. Green indicates normal CO2 levels, blue indicates insufficient CO2, and yellow indicates too high CO2. 【Practical and Convenient】The package includes two 5*5 cm glass CO2 test rods. Whether you are a professional aquarist or a beginner in fish keeping, you can easily get started and use it. Color: Transparent; Animal Type: Fish; Warranty: 2.0; Water Quality: Freshwater