Iron and trace element are grouped as micronutrients for plants. This means that they are needed in low concentration. That being said, they still play an important role in plant growth and health.
Iron
Iron is used by plants to synthesize chlorophyll as well as other enzymatic and metabolic functions. Plants with iron deficiency will often have yellowish new leaves or veins and this is usually not caused by lack of iron but actually lack of iron in the form that can be absorbed by plants. Seachem Flourish Iron consists of iron in the form of fe2+ (ferrous gluconate iron) which can be easily absorbed and utilized by plants.
Trace Element
Each element plays a different role. From promoting nutrients absorption to disease resistant. Although they have different functions, they only work together. Which is why it is important to have a balanced blend of trace elements for plants. Seachem Flourish Trace provides the necessary blend of trace elements that is essential for plants.
How to use
Iron and trace element are part of micronutrients. Unlike macronutrients they don't need to be kept in a certain concentration. Dose according to the recommended dosage once or twice a week should be more than sufficient to keep the plants healthy. Start with once a week after water change and if there’s any sign of deficiency, increase the frequency of dose. For most aquariums, once or twice a week should be sufficient while some with rapid growing plants might require more frequent dosing. Micronutrients are rapidly absorbed by plants therefore it is not too late to add dosage when there’s any sign of deficiency.