The endorheic basin lakes are called soda or alkaline lakes when the water inflows contain high concentrations of NaCO. The pH of the soda lake water is generally above 9 and sometimes the salinity is close to brackish water due to depletion of pure water by solar evaporation.
Soda lakes are rich with algal growth due to enhanced availability of dissolved CO in the lake water compared to fresh water or saline water lakes. Sodium carbonate and sodium hydroxide are in equilibrium with availability of dissolved carbon dioxide as given below in the chemical reaction
* NaCO +  HO  
* NaHCO 
During day time when sun light is available, Algae undergoes photosynthesis process which absorbs CO to shift the reaction towards NaOH formation and vice versa takes place during night time with the release of CO from the respiration process of Algae towards NaCO and NaHCO formation. In soda lake waters, carbonates of sodium act as catalyst for the algae growth by providing favourable higher concentration of dissolved CO during the day time. Due to fluctuation in dissolved CO, the pH and alkalinity of the water also keep varying.