API CO₂ Booster Carbon deficiency is one of the leading causes of poor plant growth in aquariums. API CO₂ Booster has essential liquid carbon for planted aquariums to fuel the photosynthetic process and turn light energy into new plant growth. API CO₂ Booster product supplies simple carbon compounds and slowly releases CO₂ to aquarium plants. It may safely be used alone or in conjunction with CO₂ systems. Safe for use with freshwater fish, and will not alter pH.