According to Hardy-Schulze law

‘The greater the valence of the flocculating ion added, the greater is its power to cause precipitation.’

As this law takes into consideration of only the charge present on the ion and not the size of the ion. So when the size of the atom is considered, smaller the size of an atom more will be its polarising power.

So Hardy-Schulze can be modified in terms of the polarising power of the flocculating ion as ‘The greater the polarising power of the flocculating ion added, the greater is its power to cause precipitation.’