Yes. More precisely, given a positive value p > 0, you can choose a "w" such that adding w% of water dilutes it to p% potato. Or another way - given you pour w

Yes. More precisely, given a positive value p > 0, you can choose a "w" such that adding w% of water dilutes it to p% potato. Or another way - given you pour water in at any constant rate forever, given any p% you want to dilute to, there will be a point in time where that dilution level is exceeded, and will remain so for every point in time after that.