Coral Essentials Coral Power Trace AFind The Coral Essentials Dosing Calculator Here Our Coral Essentials, Coral Power Trace A is a blend of strontium (50,000 ppm) and barium. Strontium in natural sea water is in the order of 8 10ppm. Keeping strontium at this level is advisable and not outside the range of 5 15ppm. Anecdotal evidence has shown that strontium at below 5ppm in the marine aquarium is detrimental to coral growth. For the advanced aquarist strontium levels in marine tanks