The measure which indicates whether water is acidic or basic is known as pH. More precisely, pH indicates the hydrogen ion concentration in water and is defined as the negative logarithm of the molar hydrogen ion concentration (-log [H+]).
Water is considered acidic when pH is below 7 and basic when pH is above 7. Most pH values encountered fall between O and 14. The recommended pH range for aquaculture is 6.5 to 9.0 (Figure 1).