Does Holy Water stay Holy if you keep adding tap water to it?

Question from M Kim on 2/17/2008:  
Dear Father Does Holy Water retain its "blessedness" if one keeps adding tap water to it? Is there a limit as to how much to add? Thanks M Kim
Answer by Fr. Robert J. Levis on 2/18/2008: 
M Kim, I am told one can add common water to blessed Holy Water provided you don't add more than 50% common water. Fr. Bob Levis