Artificial seawater salt pre-mix (User supplies NaCl) with an ionic composition corresponding to open ocean values, mixing to a final salinity value of 35.2. 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. Clean; no residue in mixing vessels (applies to all Formul8 and Formul8x blends).