Discussions tagged with 'mud mask' NoviceKarel Lowering natural mud PH 7.0 -> 5.3 with Citric Acid. Unstabilty problem NoviceKarel replied 5 years, 8 months ago 1 Member · 0 Replies Formulating Zink Best preservative for pH > 7 liquid mud / clay face masks? beautynerd replied 9 years, 7 months ago 5 Members · 7 Replies Formulating Viewing 1 - 2 of 2 discussions