Feature:1. DIRECT USE: Aquarium CO2 indicator solution can be used directly without dilution, avoiding the effect of different water quality.2. FAST REACT SPEED: Fish tank CO2 indicator solution is easy to use, just squeeze and drop the solution out of the bottle. Fast react time, results can be displayed in 23 hours.3. CO2 INDICATOR SOLUTION: The blue, green and yellow react solution corresponds to low, medium and high CO2 concentration, so you can identify the CO2 concentration at a glance.4. LONG TERM MONITORING: CO2 indicator solution can monitor the CO2 concentration in your fish tank for a long time, which is very important for the health of your plants and fish.5. COMPACT APPEARANCE: Portable CO2 indicator solution is compact and easy to store, making it a must have for all aquarium owners.Specification:Item Type: Aquarium CO2 Indicator SolutionBottle Material: Plastic.Package List:1 xAquarium CO2 Indicator Solution