A drop checker is a simple yet essential tool used in planted aquariums to monitor CO₂ (carbon dioxide) levels in the water. It ensures that plants receive the right amount of CO₂ for healthy growth while preventing over- or under-dosing.
How a Drop Checker Works:
It consists of a glass or plastic chamber filled with a CO₂ indicator solution and placed inside the aquarium.
The solution changes color based on the CO₂ concentration in the water:
Blue → Too little CO₂
Green → Optimal CO₂ level (ideal for plant growth)
Yellow → Too much CO₂ (dangerous for fish)
Key Features of a Good Drop Checker:
✔ Easy to Use – Just fill it with indicator solution and attach it inside the tank.
✔ Real-Time Monitoring – Provides continuous CO₂ level tracking.
✔ Accurate Color Indicators – Helps maintain a balanced CO₂ injection for healthy plants.
✔ Glass or Plastic Material – Glass is more aesthetic and durable, while plastic is lightweight and affordable.
✔ Reusable – Only requires periodic refilling of the indicator solution.