Figure shows a comparison of while light images of the proliferation of the cells treated with the extraction solution at two concentrations for 72 hours. Consistent with the viability results, the hydrogel did not exhibit a significant toxic or affect cell viability and attachment. Overall, the data in the present study suggest that the prepared hydrogel can be considered a biocompatible material and that it should be further evaluated. We observed that urazole changing its potassium ions with ion in the medium over time. Possible mechanism is shown in scheme 2. It is expected that urazole's unique ionic character selectively binds to higher valent ions and releases its potassium ions. Ion-chromatography analyses shown that urazole potassium gel can remove Ca +2 and Mg +2 ions completely, Na + partially from the tap water in exchange with K + ions (Fig. ). This shows that urazole can be used to reduce water hardness. We also tested effect of urazole on water hardness with commercially available water hardness test kits. The results showed that urazole potassium gel (1% w/w), reduces the water hardness of tap water from 3.6°dH to 1.3°dH when gel was kept in water for 12 hours. When gels were kept for 36 hours, the water hardness reduced to 0.1 °dH for the same amount of the gels.