Water potential and solute potential of two solutions can be compared by keeping the two solutions separated by a semi-permeable membrane like egg membrane at a constant pressure. The net direction and rate of flow of water between the solutions can be used to compare the water potential and solute potential. Water always moves from the system containing water at a higher water potential to the one at a lower water potential. In case of solute potential, water moves from a system with the lower solute potential to the one with higher solute potential.