Correlation of Water Quality Parameters on Growth Performance of Seaweed (Kappaphycus alvarezii Doty, 1986) Cultivated with Diagonal Method

Kappaphycus alvarezii seaweed is an exported commodity that has economic value and is a leading commodity in aquaculture. The present study aims to analyze the correlation between water quality parameters and the growth of Kappaphycus alvarezii seaweed using the diagonal method. A completely randomized design using three treatments and four replications was applied for the experimental design. The research was carried out from May to June 2023 in the waters of Angkue Village, Bone Regency, Indonesia. Treatment in this diagonal model was based on the length of the diagonal rope, namely 2.5 m (treatment 1), 3.5 m (treatment 2), and 4.5 m (treatment 3) of the water depth and seaweed maintained for 42 days at a water depth of five meters. The results showed that the absolute growth of seaweed was 17,537.0 g during the study, with an average of 5845.67 ± 359.34 g. In treatment 1, the absolute growth was 1368.55 ± 5.29 g; in treatment 2, it was 1467.83 ± 4.58 g; and in treatment 3, it was 1547.88 ± 1.24 g, with the highest growth rate and the lowest growth rate in the first week. Water quality parameters all contribute positively to seaweed growth, but those that contribute most strongly to seaweed growth are brightness, phosphate, nitrate, and salinity.