Reverse Osmosis household drinking water purification systems are commonly used for improving water for drinking and cooking. Such systems typically include a number of steps: A sediment filter to trap particles including rust and calcium carbonate optionally a second sediment filter with smaller pores. An activated carbon filter to trap organic chemicals, and chlorine which will attack and degrade TFC reverse osmosis membranes A reverse osmosis (RO) filter which is a thin film composite membrane (TFM or TFC) Optionally a second carbon filter to capture those chemicals not removed by the RO membrane. Optionally an ultra-violet lamp is used for disinfection of any microbes that may escape filtering by the reverse osmosis membrane.