Rapid urbanization has led to increasing water pollution, particularly from domestic wastewater, necessitating cost-effective and eco-friendly treatment solutions. This study explores the potential of eco enzymes derived from sweet orange, mango, lemon, tree tomato, and rose apple peels for improving water quality in Cimpago Lake, Padang, West Sumatra, Indonesia, which is affected by residential wastewater discharge. An eco enzymes were produced through a fermentation process using molasses, fruit peels, and water in a ratio of 1:3:10 over a fixed period. The fermentation process enhances the production of bio-active compounds, which aid in the degradation of organic pollutants. The initial concentrations of pH, DO, temperature and Chemical Oxygen Demand (COD) in the contaminated water were 6.2 mg/L, 5.9 mg/L, 23.9 mg/L, and 57.3 mg/L, respectively. The experimental study was conducted using artificial lake wastewater to simulate the polluted conditions of Cimpago Lake. The treatment was carried out in a batch system with five different concentrations of eco enzyme 5, 10, 15, 20, and 25%. Initial water quality parameters included pH (6.2), dissolved oxygen (DO, 5.9 mg/L), temperature (23.9 °C), and chemical oxygen demand (COD, 57.3 mg/L). Following treatment, significant improvements were observed. The pH increased from an average of 6.4 to above 9.5, approaching optimal conditions for aquatic life. DO levels exhibited a slight increase, indicating improved aeration and reduced biological oxygen demand. Temperature remained relatively stable throughout the experiment. Most notably, COD values—initially ranging from 43.17 to 58.44 mg/L—decreased substantially to 27.7–32.77 mg/L, with the most effective reduction observed at a 25% eco enzyme concentration.