Supplied Premium Plant Fertilizer
Urea, potassium ion (K+) is a relatively common ion , phosphate (PO43-) can also be absorbed by plants,
Micro nutrients
Traces of iron (Fe), manganese (Mn), zinc (Zn), boron (B), copper (Cu) and molybdenum (Mo) are generally found in fish food. Micronutrients are typically chelated, meaning a chemical shell is formed around the nutrient that makes them less reactive and less likely to fall out of solution by forming insoluble salts with phosphate. The most common chelator is EDTA.
Generally abundant and/or less relevant
Calcium (as Ca2+), magnesium,(Mg2+), sulfate (SO42-) and chloride (Cl-) are all common ions in most tap waters and are rarely ever fertilized. The only real use is to add an extra bit of magnesium when your water is soft and the tank full of fast-growing plants. Nickel (Ni) and cobalt (Co) are needed for processing urea and for the growth of nitrogen-fixing bacteria. Some fertilizers do contain these elements even though they are almost entirely unnecessary to aquatic plants.