Ikan nila (oreochromis niloticus) salah satu ikan air tawar yang mendapat perhatian cukup besar dari pemerintah yang diharapkan dapat menyumbang peningkatan produksi. penelitian ini bertujuan untuk mengkaji penurunan kadar amoniak pada sistem akuaponik dengan menggunakan kepadatan kangkung yang berbeda untuk perbaikan kualitas air. penelitian terdiri dari tiga perlakuan, yaitu perlakuan kontrol, akuaponik kepadatan 20 rumpun kangkung dan akuaponik kepadatan 40 rumpun kangkung. hasil pengukuran konsentrasi amoniak pada perlakuan kontrol sebesar 0,504 mg/l, perlakuan akuaponik kepadatan 20 rumpun kangkung sebesar 0,343 mg/l dan perlakuan akuaponik kepadatan 40 rumpun kangkung sebesar 0,272 mg/l. sedangkan untuk pengukuran parameter lainnya, meliputi suhu berkisar 25-28 c, oksigen terlarut (do) berkisar 3.5-5.7 mg/l, ph berkisar 7.6-8.0 dan nitrit berkisar 0.20-1.30 mg/l. pertumbuhan bobot dan panjang ikan tertinggi diperoleh pada perlakuan akuaponik dengan kepadatan 40 rumpun kangkung, yaitu sebesar 9.2 g dan 3.4 cm. nilai pertumbuhan kangkung berkisar 9.74-9.82 cm. penurunan kadar amoniak dengan kepadatan rumpun kangkung yang berbeda sangat efektif untuk memperbaiki mutu kualitas air. kata kunci: ikan nila, kangkung, kualitas air, pertumbuhan

Tilapia (oreochromis niloticus) was one of the freshwater fishes that received attention from the government which is expected to contribute to increased production. the study purposed to evaluated o the reduction in ammonia levels in the aquaponic system by using different densities of ipomoea aquatica to improved the water quality. the study consisted of three treatments, such as control with aquaponics, aquaponics systems with a density of 20 clams of i. aquatica and the last aquaponics systems with a density of 40 clams of i. aquatica. the results of the ammonia concentration in the control treatment were 0.504 mg/l, aquaponic systems with 20 clumps were 0.343 mg/l and aquaponic systems of 40 clumps were 0.272 mg/l. the other parameter quality waters, like; temperature have a range of about 25-28oc, dissolved oxygen (do) was 3.5-5.7 mg/l, there was an increase in ph from 7.6 to 8.0 and, the range of nitrite was an about 0.20 to 1.30 mg/l. the highest average weight and length of fish were obtained at the aquaponic system with densities 40 clumps of i. aquatica, which are 9.2 g and 3.4 cm. the growth rate of i. aquatica was 9.74-9.82 cm. it was shown reducing ammonia levels with different densities of i. aquatica clumps is very effective for improving water quality. keywords: growth, ipomea aquatica, tilapia, water quality