The influence of chelating agents like ethylene diamine tetraacetic acid (EDTA), nitrilo triacetic acid (NTA) and dimethyl sulfoxide (DMSO) on potassium sulfate solution has been analyzed. The enhancement of metastable zone width with the addition of chelaters has been observed. The variation of pH with the addition of chelaters has been monitored. The nucleation parameters were calculated from the measurements of the dependence of the metastable zone width on different cooling rates.