What is the optimal pH for most aquatic plants and animals?
1. Most living organisms require a pH that is near neutral (pH=7). Pure deionized water has a pH that is neutral because it has an equal number of hydrogen (H+) and hydroxide (OH-) ions. 2. A pH level between 6.5-7.5 is considered to be excellent. 3. A pH level between 6.0-6.4 or 7.6-8.0 is considered to be good. 4. A pH level between 5.5-5.9 or 8.1-8.5 is considered to be fair. 5. When the water becomes too acidic (pH=0-7) or basic (pH=7-14), few organisms survive. Serious problems occur when the pH is below 5 or above 8.5. What factors are affected by your watershed s pH? 1. Most aquatic organisms are adapted to a specific pH level. When the pH increases or decreases rapidly, the diversity of a water ecosystem can change dramatically. 2. Immature stages of aquatic insects and young fish are extremely sensitive to low pH values, thus, pH can affect hatching and development of aquatic animals. Fish larvae and eggs usually have a narrower pH requirement than adult fish. Also, the optima
