Hybrid RAS Outdoor

The hybrid outdoor RAS design consists of one HDPE-lined production pond, and three treatment and water recycling ponds that allow for 0.5 – 1.0 water exchanges/day. Heavy aeration to keep particles in suspension and high oxygen levels and in situ foam fractionation maintain near clear water conditions in the production pond allowing for high densities and lower chance for bacterial infections of animals. This design includes benefits of biofloc culture without the use of biofloc. One half of the land is dedicated to production, while the remaining for water treatment and recycling. Production densities are over 10 times that of typical pond culture and near 1.5 times that of biofloc culture.

The hybrid outdoor RAS is currently designed for the Pacific white shrimp, Litopenaeus vannamei, and is applicable to any other fresh or brackish water shrimp or fish species, including the Nile tilapia (Oreochromis niloticus) or tiger shrimp (Penaeus monodon). Production densities, cycles, and costs will be different for each species. For P. vannamei and depending on the location of site, up to 3 growout cycles per year can be achieved at a final harvest density of a minimum 5 kg/m3 to a maximum of 8 kg/m3 as currently designed.

Comparison For Shrimp

Metric	Hybrid RAS	Biofloc	Typical Pond Culture (India)
Production pond Size (m3)	10,000	10,000	10,000
Total land area used (ha)	2.0	1.0	1.0
Treatment ponds (ha)	1.0	N/A	N/A
Harvest density (kg/m3)	5 - 8	3 - 7	0.38
Harvest density (kg/m3)	50	20 - 30	3.8
Total production/yr (MT)	100	50	7.6
Water recycling	0.5 -1.0/d	No	No
FCR	1.2 – 1.3	1.2 – 1.6	1.5 – 1.8
Survival (%)	85 - 95	70 - 85	40-60%