aquapuri 5 series satisfy all of your needs with a versatile product range while ensuring excellent water quality and user-friendly operation. The tank-less integrated models (541/551 series) produce Type I grade water from tap water by eliminating the possibility of tank contamination. aquapuri 5 WPS monitors resistivity (or conductivity) with temperature in real-time for you to keep tracking the water quality. In the flow diagram, the lifetime of each filter is indicated by color so you can be ready for the filter replacement.