<![CDATA[Chlorella vulgaris can utilize organic substances contained in waste rubber which serves as a medium for its growth. C. vulgaris is one of the types of microalgae that can be used as raw material forage and natural forage fish. This research aims to utilize crumb rubber industry wastewater as a medium for the growth of C. vulgaris natural forage fish. The initial phase of the research, namely the preparation of pure isolates of C. vulgaris, followed by the rejuvenation to log phase, carried out to scale up biomass obtained from cultures of C. vulgaris which could be used as a natural forage. The next was testing the quality of natural forage product including beta carotene, folic acid, oils and fats, fat, unsaturated fat, protein, moisture content, ash content, chlorophyll, crude fiber, iron (Fe), manganese (Mn), potassium and vitamin and the wasted residual of the media used. The results of the test for protein content and moisture content of C. vulgaris fish forage by utilizing the waste water of crumb rubber industry respectively were 2.3% and 95.46%. While the quality of the natural forage product produced were unsaturated fatty 0.44 mg / kg; 2.3% protein; fatty oils 141 mg / L; chlorophyll a 2.7094 mg / L; chlorophyll b, 0.8424 mg / L and vitamin B1 3.99 mg / kg; Vitamin D 2.52 mg / 100 g and Vitamin E 1.09 mg / 100 g.Keywords : the waste, C. vulgaris, natural forage fishAbstrakChlorella vulgaris dapat memanfaatkan bahan-bahan organik yang terdapat di dalam limbah karet yang berfungsi sebagai media pertumbuhan C. vulgaris. C. vulgaris adalah salah satu jenis mikroalga yang dapat digunakan sabagai bahan baku pakan dan pakan alami ikan. Penelitian ini bertujuan memanfaatkan limbah cair industri karet remah sebagai media pertumbuhan C. vulgaris untuk pakan alami ikan. Tahap awal penelitian yaitu penyiapan isolat murni C. vulgaris, selanjutnya dilakukan peremajaan sampai fase log, dilakukan scale up sampai diperoleh biomassa dari kultur C. vulgaris yang dapat digunakan sebagai pakan alami. Selanjutnya dilakukan pengujian terhadap mutu pakan alami yang dihasilkan meliputi beta karoten, asam folat, minyak dan lemak, kadar lemak, lemak tak jenuh, protein, kadar air, kadar abu, khlorofil, serat kasar, Besi (Fe), Mangan (Mn), kalium, vitamin dan limbah sisa dari media yang digunakan. Hasil pengujian kadar protein dan kadar air pakan ikan C. vulgaris dengan memanfaatkan limbah cair industri karet remah berturut-turut yaitu 2,3% dan 95,46%. Sedangkan mutu pakan alami yang dihasilkan yaitu lemak tak jenuh 0,44 mg/kg; protein 2,3%; minyak lemak 141 mg/L; khlorofil a 2,7094 mg/L; khlorofil b, 0,8424 mg/L dan vitamin B1 3,99 mg/Kg; Vitamin D 2,52 mg/100 g dan Vitamin E 1,09 mg/100 g.Kata Kunci : limbah cair, C. vulgaris, pakan alami ikan]]>
