Limbah industri dan pertanian yang dibuang ke lingkungan perairan merupakan masalah yang sering muncul pada pencemaran lingkungan budidaya. Sehingga kualitas air berpengaruh pada pertumbuhan dan keberlangsungan hidup pada aktivitas budidaya. Tujuan penelitian yaitu memanfaatkan rumput laut jenis K. alvarezii sebagai biofilterasi sehingga mampu memperbaiki kualitas air pada budidaya perairan. Penelitian ini menggunakan rumput laut jenis Kappaphycus alvarezii sebagai bioflter dengan berat P1 100, P2 200, dan P3 300 gram. Parameter kualitas air seperti pH, suhu, DO, nitrat, nitrit, dan amoniak yang ada pada masing-masing perlakuan telah diamati dan dibandingkan. Analisis data menggunakan Analisis Varian (ANOVA) bersama dengan Rancangan Acak Lengkap (RAL). Hasil penelitian kualitas air selama 4 hari mengunakan rumput laut sebagai biofilter pada pengamatan parameter suhu pada tiap perlakuan menunjukkan nilai yang cenderung meningkat. P3 memiliki suhu tertingi 27,8 oC sedangkan P0 memiliki suhu terendah 26,2 oC. Nilai pH selama penelitian berkisar 8. Nilai pH cukup mendukung dalam usaha budidaya. Bahwa nilai pH yang baik bagi pertumbuhan berkisar 6–9 pada perairan. Kisaran DO pada penelitan diperoleh antara 4,48 – 4,76 mg/l. Adapun kandungan nitrat (NO3) tertinggi dihasilkan oleh P0 yaitu (0,16) dan kandungan nitrat terendah dihasilkan oleh perlakuan P1 (0,12) P2 (0,14) P3 (0,15). Hasil pengujian nitrit yang telah didapatkan pada perlakuan P0 (0,015) P1 (0,09) P2 (0,019) dan P3 (0,021). pengamatan nilai amoniak yang didapatkan dalam pengujian yaitu pada perlakuan P0 (1,02) P1 (0,73) P2 (1,28) dan P3 (1,32) mg/l. berdasarkan hasil penelitian diatas, dapat disimpulkan bahwa penelitian mengenai penggunaan rumput laut sebagai biofilter (K. alvarezii) pada penelitian mampu untuk meminimalisir kualitas air dalam budidaya.
Kata Kunci: Limbah, Kualitas Air, Rumput Laut, Biofilter

Industrial and agricultural waste that is dumped into the aquatic environment is a problem that often appears in the pollution of the agricultural environment. Therefore, the growth and survival of the farming activity are impacted by the water quality. The objective of the study was to investigate the application of K. alvarezii seaweed as biofiltration to enhance the water quality in aquaculture. This research used K.alvarezii seaweed as a biofilter weighing P1 100, P2 200, and P3 300 grams. Water quality parameters such as pH, temperature, DO, nitrate, nitrite, and ammonia in each treatment were observed and compared. Data were analyzed using Analysis of Variance (ANOVA) together with Randomized Complete Design (RAL). The results of the water quality research for 4 days using the seaweed as a biofilter in the observation of temperature parameters in each treatment showed that the value tended to increase. P3 had the highest temperature of 27.8 ℃ while POhad the lowest temperature of 26.2C. The pH value during the research was around8.The pH value was quite supportive in the cultivation business. The pH value that was good for growth was around 6-9 in water. The range of DO in the research was obtained between 4.48 -4.76 mg/l. The highest nitrate content (NO3) produced by PO was (0.16) and the lowest nitrate content was produced by treatment P1 (0.12) P2 (0.14) P3 (0.15). The results of nitrite testing that was obtained in treatment PO (0.015), P1 (0.09), P2 (0.019) and P3 (0.021). Observation of the value of ammonia obtained in the test was in the treatment PO (1.02), P1 (0.73), P2(1.28) and P3(1.32) mg/l. Based on these results, it could be concluded that the research on the use of seaweed (K. alvarezii) as a biofilter was able to minimize the quality of water incultivation. Keywords: Waste, Water Quality, Seaweed, Biofilter