Removal of wastes from pond bottom
Wastes accumulated in the pond during the previous crop should be removed because they are the result of decayed or uneaten feed, dead and decaying plankton/algae, and fecal matter from shrimp. They form a layer on the soil that is black in color and produces a foul odor. These wastes release toxic substances such as hydrogen sulfide and ammonia into the pond, leading to stress or death for shrimp.
After harvest, all dead shrimp should be removed. Sludge and organic matter should be pumped from the pond or manually removed. Lined ponds must be disinfected with chlorinated water and allowed to dry. Earthen ponds need to be dried before filling, limed after each grow out, and plowed at least once per year. Earthen ponds need to have soil pH tested to determine the amount of lime required for disinfection, acidity reduction, and accelerated mineralization.
Sun drying the pond bottom
Sun drying the pond bottom is the most effective method of eliminating undesirable species, their eggs, and pathogens prior to restocking. Drying also oxidizes undesirable chemical substances, helps mineralize organic matter, and aids in the restoration of pond pH back to more neutral conditions.
Certain soil conditions and the impact of water tables may require special soil treatment. Please contact your local BiOWiSH representative, or reference our online tools for best pond preparation liming, pH, and soil preparation.
Ponds with a lined bottom cannot be dried and need to be disinfected using a chlorine solution. After disinfecting and rinsing, water should be drained and waste should be pumped into a waste reservoir.