Artificial Sea Water
Molar Salt G/Liter
0.425 sodium chloride 24.6
0.009 potassium chloride 0.67
0.0093 calcium chloride * 2H2O 1.36
0.0255 magnesium sulfate * 7H2O 6.29
0.023 magnesium chloride * 6H2O 4.66
0.002 sodium bicarbonate 0.18

Use a pH meter to bring pH to 8.0.

see the supplier list.