Same as figure 6 but for [Fe/H] = −0.5 (left) and [Fe/H] = 0.5 (right). The water content in the disc changes very little with [Fe/H] when excluding iron oxidation as discussed in section 7.3 while a slight increase in the water mass fraction can be seen for the metal-poor star when including iron oxidation. Further, due to the increased iron content, the mass fraction of fayalite (and forsterite from the reaction shown in (39)) is increased in the metal-rich star.