As the pH is reduced, further protonation and condensation to polyvanadates occur: at pH 4-6 [H2VO4]− is predominant at pV greater than ca. 4, while at higher concentrations trimers and tetramers are formed.
With decreasing pH, the formation of polyvanadates continues through protonation and condensation. At a pH range of 4-6, [H2VO4]− is dominant, while at higher concentrations, trimers and tetramers become more prevalent.