The EHEIM CO2-Set is a comprehensive CO₂ fertilisation system designed to support strong, healthy plant growth in freshwater aquariums. It includes a precision pressure reducer, safety hose, diffuser with bubble counter and non-return valve, CO₂ long-term test kit and multiple water test strips. The system comes in different sizes to suit tanks up to 200L, 400L or 600L, offering either a disposable bottle option or a reusable refillable bottle option. With easy tool-free installation and built-in safety features, this set offers reliable CO₂ dosing and monitoring so your aquatic plants receive one of their most essential nutrients while aquascape clarity and stability are maintained.