Inoculation process involves cultivation of algae strains in a pilot scale to optimize the growth conditions under external environment.
In the inoculation stage, small raceway ponds lined with HDPE plastic are used for cultivation. Here, adequate nutrients – nitrogen, phosphorus, potassium, and superphosphate are added and CO2 is bubbled into the hypersaline water. Continuous mixing is achieved with the help of paddlewheels.
For raceway ponds, long arm, slow revolution paddle wheels are used for uniform mixing. Vertical mixing is an important factor for the algal growth because it influences the frequency by which cell will travel from bottom (dark zone – no photosynthesis) to surface (light zone - photosynthesis) of the open pond.
Once the algae get adapted to the environmental conditions and normal growth and required cell density is achieved, the algae are shifted to larger raceway ponds for mass cultivation.