Kualitas Air dan Proksimat Rumput Laut Hijau (Ulva lactuca) dalam Matriks Natrium Alginat dengan Variasi Dosis NPK

Abstract

Ulva lactuca (sea lettuce) has significant potential in various fields due to its high nutritional content. This study aims to analyze the effect of varying NPK fertilizer doses on the cultivation of U. lactuca in a natrium alginate matrix on physicochemical parameters and proximate composition. The cultivation period lasted 60 days, with weekly analysis of physicochemical parameters, chemical parameters analyzed using spectrophotometry, and proximate analysis conducted at the end of the cultivation. Result of the research, pH and dissolved oxygen (DO) remained within the ideal range, while temperature and salinity were slightly above optimal levels. The highest recorded concentrations were 0.0232 ppm for ammonia, 0.8368 ppm for nitrite, 10.786 ppm for nitrate, and 0.494 ppm for phosphate. The highest proximate values were 6.07% for moisture, 19.33% for ash, 8.09% for protein, 2.76% for lipid, and 67.89% for carbohydrate. The application of NPK fertilizer provided favorable nutrient concentrations for the growth of Ulva sp., particularly for ammonia, nitrate, and phosphate. However, nitrite levels exceeded the optimal threshold. Among treatments, the 20 ppm NPK dosage yielded the best overall results.

Ulva lactuca (selada laut) memiliki potensi yang besar dalam berbagai bidang karena kandungan nutrisinya yang tinggi. Penelitian ini bertujuan menganalisis pengaruh variasi dosis pupuk NPK pada budidaya U. lactuca dalam matriks natrium alginat terhadap parameter fisika-kimia dan kandungan proksimat. Pemeliharaan dilakukan selama 60 hari, analisis parameter fisika-kimia dilakukan satu minggu sekali, analisis konsentrasi nutrisi dengan metode spektrofotometer, analisis proksimat dilakukan pada akhir pemeliharaan. Hasil dari penelitian ini, pH dan DO berada dalam rentang ideal, suhu dan salinitas sedikit lebih tinggi dari batas ideal. Konsentrasi amonia tertinggi sebesar 0,0232 ppm, nitrit 0,8368 ppm, nitrat 10,786 ppm, dan fosfat 0,494 ppm. Kadar air tertinggi 6,07%, kadar abu 19,33%, protein 8,09%, lemak 2,76%, dan karbohidrat 67,89%. Pemberian pupuk NPK memberikan konsentrasi nitrat dan fosfat ideal untuk pertumbuhan Ulva sp.. Konsentrasi amonia di bawah rentang ideal dan nitrit lebih tinggi dari batas ideal. Pupuk NPK 20 ppm menunjukkan hasil terbaik.