i start first. Hi Timi! Know u since formula botanica. For me, preservation is quite frustrating bcos i need to know which one to use: - which preservative preserve what? - which preservative is pH sensitive? - how much % do i need? - do i need to mix with other preservatives? - do i really need to do microbial test? - then, how long does my product last? omg. it's overwhelming even for a not-so-beginner formulator!