This paper presents a theory that links solution complexation equilibria with a model for precipitation predicting the panicle size distribution. This model uses classical nucleation theory and growth rates by various rate limiting steps for the growth of the crystals. This model is compared to forced hydrolysis experiments where dilute Indium nitrate solutions, acidified with nitric acid, were heated to 80°C. The experiments produced cubic particles of Indium hydroxide. The experiments were monitored for temperature, pH. turbidity, indium concentration in solution and particle size distribution, all as a function of lime for comparison with this model. The model gives an accurate prediction of the evolution of the particle size distribution, pH, turbidity, and indium concentration with time.