Struvite was continuously pptd. from aq. solns. of phosphates in presence of B, Co, Mn and Mo salts contained in liq. manure. The B, Co and Mo compds. (in contrast to Mn compds.) favored well-formed struvite crystals. Neither Co nor Mo changed the std. geometrical proportions of struvite crystals, while Mn and B increased the proportions. Struvite crystn. run well in the presence of B. The linear growth rate was more than 2.10(-8) m/s, and the nucleation rate was less than 2.10(8) 1/(s.m(3)). Co and Mn were sepd. as hydroxides and their content in solid phase was 393 mg/kg and 749 mg/kg Mn, resp.