Contains all the essential macro and trace elements that are naturally present in the correct ratios for your fish and corals. Laboratory tested values. Natural live marine bacteria. Ready for immediate use. It can be mixed with sea water prepared with synthetic or natural salt. Also suitable for Mediterranean aquariums. In tropical marine aquariums it is possible to add 1.2 liters of reverse osmosis water for each 20 liter package to obtain an ideal salinity. However, since the skimmer tends to make it go down, this method is not necessary. Reference analysis (may have small variations according to seasonality and draft): pH 7.86 • Salinity 37.23 • Chloride 21022 mg/l • Boron 4.89 mg/lt • Magnesium 1376 • Sulfur 988mg/lt • Calcium 450.8 • Sodium 11844 mg/lt l • Potassium 440.7 • Fluorine 1.43mg/lt • Bromine 73.38 mg/lt • Strontium 8.49 mg/lt