As water temperature and pH increase, what happens to unionized ammonia?

As water temperature and pH increase, the concentration of unionized ammonia also increases. This relationship is critical in aquaculture because unionized ammonia (NH3) is more toxic to aquatic organisms compared to its ionized form, ammonium (NH4+).

At higher temperatures, the solubility of gases typically decreases, and chemical equilibrium shifts can favor the formation of unionized ammonia. Additionally, as pH rises, the equilibrium also shifts towards more unionized ammonia, as the reaction that converts ammonium to unionized ammonia is pH dependent.

This increase in unionized ammonia due to higher temperature and pH levels poses a significant risk to fish and other aquatic life, requiring careful monitoring and management in aquaculture systems. Maintaining optimal water quality conditions is essential to ensure the health and growth of cultured organisms.