Optimal Dietary Protein/Energy Ratio and Phosphorus Level on Water Quality and Output for a Hybrid Grouper (Epinephelus lanceolatus ♂ × Epinephelus fuscoguttatus ♀) Recirculating Aquaculture System

In a recirculating aquaculture system (RAS), feed is critical to the growth of fish and main source nutrient pollutants in water. An eight-week feeding trial was conducted investigate role on efficiency hybrid grouper (Epinephelus lanceolatus ♂ × Epinephelus fuscoguttatus ♀) water quality RAS. Five commercial feeds with different respective dietary protein/energy (P/E) ratios available phosphorus levels were selected (LNLP, 31.97 g/MJ, 0.96%; LNMP, 32.11 1.54%; MNLP, 36.26 0.98%; MNMP, 36.53 1.58%; HNP, 41.54 1.97%). The results showed that HNP had highest MNLP provided best economic benefit. trend within 6 h after similar among five groups. relative concentrations ammonia nitrogen, total active phosphate, reached maximum 2 feeding, concentration nitrite 1 feeding. high P/E ratio increased nitrogen nitrogen. much higher than those other treatments. no significant effect concentration. High water, but phosphate observed. Considering efficiency, benefit, quality, it can be concluded most suitable for RAS breeding grouper. this study supplement gap effects provide data support sustainable development industry.