Pretreatment of urine is required in space station waste water recovery systems to control odors, fix urea, and control microbial growth. Also, recent testing and experience on the shuttle orbiter waste water plumbing has discovered that pretreatment is required for long term use of urine separator hardware to reduce or eliminate fouling of the hardware and plumbing with urine precipitates. This is important for international Space Station (ISS) application because the amount of maintenance time for cleaning and repairing hardware must be minimized. This paper describes the development and initial testing of a pretreatment method produced by a trade study which looked at several different pretreatment methods. The tests used hardware previously flown as a Design Test Objective (DTO) experiment on the Orbiter.