The average pH of pure water is approximately 7, which is considered neutral on the pH scale. This means that pure water has an equal concentration of hydrogen ions \((H^+)\) and hydroxide ions \((OH^-)\), resulting in a balanced state. pH values below 7 indicate acidity, while values above 7 indicate alkalinity. The pH of water can be influenced by various factors, including temperature and dissolved substances. Maintaining a stable pH in aquatic ecosystems is crucial for the survival of organisms, as many biological processes are pH-sensitive, affecting metabolism, enzyme activity, and overall health.