Technical Abstract: The Pacific white shrimp (Litopenaeus vannamei) is being cultured in ponds far from coastal areas that have been filled with low-salinity (2-5 ppt) ground water or brine transported from the coast and diluted on site. The ionic composition of low-salinity ground water often differs from dilute seawater at the same salinity. Since deficiencies of one or several ions in low-salinity ground water can be corrected, it should be possible to add key ions to freshwater to allow successful culture of L. vannamei. A study was conducted in three 0.1-ha earthen ponds to determine whether L. vannamei could be grown to market size in ponds where concentrations of key ions were augmented to levels similar to dilute seawater at 0.8 ppt. The ponds were filled with freshwater (total alkalinity 154 mg/L as CaCO3; total hardness 188 mg/L as CaCO3). Salinity was increased to 0.7 – 0.8 ppt through addition of salt and potassium fertilizer. Stock salt applied at 5,200 kg/ha supplied sodium and chloride, while potassium fertilizer (0-0-22, 11% Mg, 22% S) applied at 3,100 kg/ha supplied potassium, magnesium, and sulfate. Ponds were stocked with PL15 shrimp at 39 PL/m2. Shrimp in all ponds were fed a commercially formulated shrimp diet (35% crude protein), 7 d/wk. The shrimp population was sampled weekly to monitor growth. Each pond was equipped with a 0.37-kW electric paddlewheel aerator, and ponds were aerated nightly to maintain dissolved oxygen concentrations above 3.0 mg/L. Addition of stock salt and potassium fertilizer raised concentrations of selected ions to levels that allowed shrimp to survive and grow. Pond salinity averaged 0.7 ppt throughout the grow out cycle. After 125 days of grow out, gross shrimp yield averaged 3,449 kg/ha and individual weight averaged 19.3 g/shrimp. Shrimp survival averaged 47%.