This study aims to evaluate the effectiveness of aquatic plants water spinach (Ipomoea aquatica) and duckweed (Lemna minor) in reducing ammonia concentration and improving water quality in common carp (Cyprinus carpio) aquaculture ponds through phytoremediation. Four treatments were tested: P1 (water spinach), P2 (duckweed), P3 (combination of both), and K (control), with observations conducted on day 0, day 7, day 14, and day 21.The results showed that treatment P1 provided the most significant reduction in ammonia concentration (from 0.12 mg/L to 0.05 mg/L), BOD (from 206 mg/L to 20.4 mg/L), COD (from 505 mg/L to 51.1 mg/L), and TDS (from 731 mg/L to 477 mg/L). Treatment P3 also demonstrated good effectiveness, particularly in reducing ammonia and COD, although not as efficiently as P1. In contrast, treatment P2 showed a sharp increase in ammonia on day 7 (6.4 mg/L), followed by a drastic decrease, indicating high fluctuation. The control treatment (K) showed no significant changes across all parameters.These findings indicate that water spinach has strong potential as a phytoremediation agent in freshwater aquaculture systems, with the ability to absorb ammonia and significantly improve water quality. This approach offers an eco-friendly and sustainable solution to enhance the efficiency and environmental health of common carp farming