Sidoarjo Regency holds significant potential for pond culture, particularly in Tambak Oso Village, Waru District. Despite this, there has been a decline in pond production in recent years, possibly caused by deteriorating pond culture water quality. Consequently, a study was undertaken to assess the quality of pond culture water and the source water in Tambak Oso Village. The study was conducted at six ponds and two rivers. The irrigation source of ponds 1, 2, and 3 are supplied by the Tambak Oso River, while ponds 4, 5, and 6 are supplied by the Buntung River. Parameters examined included water temperature, water brightness, pH, nitrate (NO3), Dissolved Oxygen (DO), and Total Organic Matter (TOM). The results indicated that all six ponds met the required quality standards, except for water temperature. The Buntung River met the quality standards for pond source water, whereas the Tambak Oso River fell short only in terms of pH. The t-test results revealed differences in water quality between pond 3 and the Tambak Oso River, as well as pond 6 and the Buntung River.