The Dennerle Bio CO2 Set is a biological carbon dioxide fertilization system designed for nano aquariums up to 60 liters (15 US gallons). It uses yeast fermentation to produce CO2, which is essential for the photosynthesis process in aquatic plants. The set includes all necessary components such as a storage depot with special gel, a bubble counter, and an injector that connects directly to Dennerle's corner filter models. This system provides a continuous supply of CO2 for at least 30 days, ensuring optimal plant health and growth without the need for complex setup or maintenance. Ideal for hobbyists who want to enhance their planted nano aquariums with minimal effort, this product is perfect for those looking to achieve lush greenery and vibrant coral in smaller tanks.