API CO2 Booster Plant 473mlAquatic plants also require carbon to fuel the photosynthetic process and turn light energy and nutrients into new plant growth. Carbon deficiency is one of the leading causes of poor plant growth in aquariums. CO2 Booster adds essential carbon in a form plants can absorb from the water. Supplies simple carbon compounds and slowly releases CO2 to the plants. Can be used alone or with CO2 systems. Safe for use with freshwater fish and will not alter pH. Simple once a day dose.