Creates the conditions for healthy plant-growth through ideal carbon fertilisation Convenient and simple application Time-tested diffusion technique provides the perfect plant-care with carbon Aids in raising the content of carbon dioxide through higher plant assimilation pH value stays at a healthy level to avoid the development of dangerous ammonia conections which raise the pH level No unsightly lime build-up on plants and aquarium walls Composed of CO2 deposit 11 g, 1 diffusion tube, 1 hose connection For aquariums up to 100 Litres. Optimat from Tetra is a economical and easy way to dose carbon dioxide to your plants. The in tank dispenser is simply refilled from the canister (refills are available)and CO2 slowly dissolves into your aquarium during the course of the day.