Artificial seawater salt pre-mix (User supplies NaCl) with an ionic composition formulated for coral growers. Concentrations of Mg, Ca, K, and Sr are linearly increased, while Na is decreased to maintain appropriate salinity value. Enhanced alkalinity. Mixes to a final salinity value of 35.4. Minor and trace elements included are specifically those not considered by researchers to be phytotoxic and which exhibit a nutrient-type depth profile in open oceanic waters.