He level of compound diet program. two.3.four. Water High-quality Management Within this study
He amount of compound diet. 2.three.four. Water Quality Management In this study, exogenous seawater or underground well water have been pumped in to the disinfection tank within the culture greenhouse. Immediately after disinfection, the water was heated through solar exposure till it reached an acceptable temperature, and it then entered the RASs as source water for the culture. The water utilised within the initial period of recirculating aquaculture was all exogenous seawater (salinity about 31). Underground effectively water (salinity about 20) was steadily added throughout the middle stage, until the salinity in the aquaculture water dropped to about 25, then the daily addition of exogenous seawater Bafilomycin C1 manufacturer gradually brought the salinity up to around 29. In an effort to sustain DO above five.0 mg/L, liquid oxygen (0.2 m3 /h, 24 h/d) was added from the 20th day of RAS culture onwards, along with the amount (0.4 m3 /h, 24 h/d) was additional elevated in the 30th day onwards. Temperature (T), dissolved oxygen (DO), salinity, and pH in 3 culture tanks randomly chosen from every RAS program (RAS1 and RAS2) had been measuredAppl. Sci. 2021, 11,6 ofusing YSI PROplus at eight:00, 14:00, and 20:00 every day. The average values represented the water good quality index of each RAS. In the course of the first ten days of RAS culture, the contents of total ammonia Cholesteryl sulfate Cancer nitrogen (TAN) and nitrite nitrogen (NO2 -N) and also the total quantity of Vibrio present in two RASs had been determined each and every five days. Involving days 11 and 20, they have been determined each two days, and amongst days 21 and 53, they were measured everyday. The total ammonia nitrogen (TAN) and nitrite nitrogen (NO2 -N) have been measured using a YSI 9500 photometer: TAN was determined within the Phot four program and nitrite nitrogen (NO2 -N) inside the Phot 24 program. The total quantity of Vibrio was calculated via plate culture on TCBS. The each day addition of liquid oxygen and ozone in the two RASs for the culture of Litopenaeus vannamei is shown in Table 1. The UV lamp was consistently on during the culture period. The initial biological media filling rate in the MBBR was 58.3 , which contained ten of mature media (the mature media have been sourced from a RAS for grouper culture using a density of 80 kg/m3 ). Around the 41st day of RAS culture, 1 m3 of new media was added to every single MBBR, as well as the filling price of biological media reached 62.five . 3. Final results 3.1. Shrimp Development Just after 1.two million post-larval shrimp (PL five) were cultured in nursery tanks for 39 days, a total of 692,000 post-larval shrimp survived (survival price, 57.5 ). A total of 685,000 post-larval shrimp were chosen and transferred for the RAS. Following 53 days of culture, 650,400 shrimp survived (survival price, 94.95 ). Through the 53-day RAS culture period, the average weight of the shrimp improved from 0.four g to 13.43 g, as well as the total biomass elevated from 274 kg to 8735 kg, so the total weight get was 8461 kg (Figure 3). Right after 92 days of culture, the yield reached 12.92 kg/m3 . The dry weight of each day feed in the two RASs is shown in Figure four. The quantity of feed progressively increased to a maximum of 270 kg. At a later stage with the culture, the feed quantity was lowered in order to retain water high quality parameters. Through the RAS culture period, a total of 7912 kg of dry weight feed 7 of 13 including 2405 kg of copepods (which were converted to a dry weight of 361 kg) and 7551 kg of commercial feed had been consumed.Appl. Sci. 2021, 11, x FOR PEER REVIEWFigure three. Changes in average body weight (A) and biomass (B) of whiteleg shrimp, L.