The hydrosphere refers to all water on the earth's surface. Water quality improves with decreased pollution from human activity. Generally, good water: - Has no odor, is tasteless, and is visibly clear - Has stable conductivity that is not significantly raised or lowered by pollutants - Has a dissolved oxygen content greater than 6 mg/L - Has a relatively neutral pH - Has low levels, if any, of suspended particulate matter (SPM) - Has a low turbidity value, which measures the relative clarity of the water in units of FNU or NTU