The design of a round-tank farm depends on the water source.  Constructing modules of round tanks is straightforward, however, the water storage and treatment system is the highest priority when designing a round-tank farm.  Although most shrimp farms are designed for open water exchange only, it is recommended to design your round-tank farm to incorporate a water recirculation system to improve efficiency and optimize sustainability.  Depending on the water source, it is recommended to have at least a 1:1 reservoir to grow-out ratio.  

Farm Design - Water flow between reservoirs - Generally, the raw seawater is pumped into a sedimentation pond (larger, the better) for initial settling.  Salinity permitting, some farmers stock this settling pond with Tilapia to further condition the water.  Barramundi or sea bass are also stocked to control the numbers of Tilapia fry from overpopulating the reservoir.  

From the settling reservoir, the effluent is pumped to a smaller 2,000 m2 pond or canal with a series of partitions or baffles to further facilitate settling of suspended solids.  The effluent overflows to a 2,000 m2 reservoir (lined with HDPE).  The effluent overflows or is pumped into a lined, chlorination reservoir (1,000 m2) where the water is chlorinated at 10 ppm active chlorine.  Some farmers have duplicate chlorination reservoirs to alternate treatments to insure a continuous flow of treated water.  After the chlorine is neutralized (usually 24 hours or less using a paddlewheel), the treated water is pumped to a conditioning reservoir and available for the round-tank module.  Stored water in the conditioning reservoir should be used within 3 days before the initiation of algae blooms.  

Recirculation - The final step in optimizing the efficiency and sustainability of this round-tank culture system is to recirculate the culture water to minimize the impact on the local ecosystem.  This same step applies to the intensive shrimp ponds in Belize as well. Recycling of culture water also enhances biosecurity which in turn reduces the risk of disease manifestation.  Moreover, this high-yield, small footprint model would suppress further shrimp farm expansion.  The existing non-functioning ponds could be utilized as intake and sedimentation reservoirs for remediating culture water, enabling farmers to continue farming in the low-lying areas that may be at risk of rising sea levels.

Round tank frame construction

Shading the round tank farm is a good idea

The advantage of round tanks is that they can be covered inside of a greenhouse structure for temperature control as well as for reducing light intensity using shade cloth or netting.  Generally, a 50-100% coverage with shade netting is recommended to reduce algae blooms.