The aim of this study was to evaluate the e ffectiveness and cost-benefit of water probiotics (Sanolife PRO W) in tilapia farming. Six earthen ponds (2100 m2 , 6500 fish each, 20±2.21 g/fish ) were used. Ponds were randomly allocated for the treatment and control, 3 ponds each. A water probiotic “Sanolife PRO W- INVE aquaculture Belgium”, a blend of Bacillus Subtilis and Bacillus Licheniformis 5x105 cfu /g, was add to the treatment ponds at a rate of 30 g per pond (50 g/feddan) every 2 weeks for 8 months, according to the manufacturer instructions.
The results revealed an improvement in the water quality especially total ammonia nitrogen and unionised ammonia in treated ponds (P<0.05). Final body weight, weight gain and feed conversion ratio were significantly (P<0.05) improved in fish treated with Sanolife PRO W. F urthermore, the fish received in water probiotic showed significant increase in total fish sales and relative percent of return (P<0.05) . The morphometric analysis of intestine showed significant improvement in the absorption capacity in fish treated with Sanolife PRO W in form of increased villi length, villi width and goblet cell number compared to control group(P<0.05).
In conclusion, using of in water probiotic (Sanolife PRO W) improved farmed water quality, Nile tilapia performance, feed utilization efficiency, total fish sales and relative percent of return .