What improvement can you suggest in the Hardy-Schulze rule?

(N/A) Schulze and Hardy observed that 'the greater the valency of the flocculating ion added,the greater is its power to cause precipitation.' This rule considers only the charge on the ion,not its size. The smaller the size of the ion,the greater is its polarising power. Thus,the Hardy-Schulze rule can be improved as follows: 'The greater the polarising power of the added flocculating ion,the greater is its precipitating power.'