Chelated or complexed traces are only the micros that are required by the plants. These are iron, zinc, magnesium, manganese, molbdenem and copper. Plants also require nitrogen, phosphorus and potassium (NPK) which can be supplied naturally by the fish or added in the forms of potassium nitrate and potassium phosphate. Calcium and magnesium are also required but normally found in the tap water. And the most important one of is carbon usually added in the form of carbon dioxide.
The EI sticky above explains in a lot more detail.
James