Struvite was pptd. from phosphate(V), Mg2+, NH4+, and K+ ions-contg. aq. solns. to det kinetic parameters of the continuous struvite reaction crystn. process calcd. from the crystal size distribution by using size - independent growth model (SIG) and Rojkowski exponential size dependent growth model (RE SDG). The K+ ions advantageously affected on linear struvite crystals growth rate. The results were compared with the process data concerning recovery of phosphate(V) ions from K+ ions-contg. liq. manure. The impurities presented in liq. manure unfavorably affected on struvite crystals growth. The RE SDG model described the distribution of the product crystal d. population much more accurately than the SIG model, but the linear growth rates of struvite crystals calcd. from both models were comparable. RE SDG model was recommended for estg. the kinetics of continuous struvite crystn. in the phosphates(V) recovery process from liq. manure.