Trace element, is referred to elements with concentration lower than 100 PPM.
Major elements, are Ca++, MG ++ , carbonates, Strontium.
traces are Iron, iodine, Molybdenum and about 60 others.
major elements, are major part which make sea water, and need to be replenished. without them, we do not have salt water.
traces, we experiment with.
I dose Iron, Iodine, and also B-Balance from Zeovit and Zeospur whichis said to contain copper.