Ketapang waters, South Lampung is one of the provinces in Indonesia that has great economic opportunities for seaweed. One of the natural products of Ketapang Waters is red seaweed (Rhodophyceae) of the type Gracilaria sp. which can produce agar. Agar is used as a stabilizer, emulsifier, gel maker, and others. The quality of agar can also be influenced by several internal and external factors. …