Low-salinity ponds: the potassium & magnesium fix

Vannamei tolerate low salinity well, but only if the water has the right mineral balance. Inland borewell water is often deficient in potassium (K) and magnesium (Mg) relative to sodium — and that imbalance stresses the shrimp, hurting survival and growth.

The target is roughly a 3:1 magnesium-to-calcium ratio and potassium at least near the seawater-diluted level. Correcting with muriate of potash and magnesium sulphate has, in documented trials, lifted survival dramatically in low-salinity culture.

Test your source water for K and Mg before stocking, dose to the target based on pond volume and the product's active content, and re-check periodically. Small mineral costs early can be the difference between a 20% and a 70% survival crop.