The osmotic pressure of the salt inside the effective volume of the polymer at the isospheric point is the same, regardless of the salt type, as can be deduced from the mechanical (pressure) equilibrium. The osmotic pressure of the reservoir depends only on the salt concentration in our model. The counter pressure originates from the polymer chain and the osmotic pressure of ions. The pressure of the polymer chain is determined by its spatial extension, thus it does not differ at the isospheric point. Hence the osmotic pressure of the ions inside the effective polymer volume has to be the same, independent of the salt type. Note, however, the net salt-effect is a sum of two large contributions (see eq 7), namely of an ideal gas and of an excess interaction, which significantly vary with the salt type (i.e., with ε anion ).