The Direct-Q 5 tap-fed water purification system is designed for scientists who need 5 to 15 L of ultrapure water per day and do not have easy access to acceptable quality pretreated water. This compact, silent system produces up to 0.6 L/min of ultrapure (Type 1) water on demand, directly from potable tap water. Direct-Q system performance characteristics are automatically monitored by pressure, temperature and resistivity sensors, and are clearly shown on the system's display, which also indicates when routine maintenance should be performed.