Macro vs. Micro Nutrients
Planted tanks require two types of fertilizers: macronutrients (nitrogen N, phosphorus P, potassium K) and micronutrients (iron, manganese, boron, zinc, and other trace elements). Most commercial liquid fertilizers are either "All-in-One" (containing both), separate micro and macro solutions, or specialized iron supplements. The Estimative Index (EI) and Perpetual Preservation Cycle (PPS-Pro) are the two most popular dosing methodologies.
Signs of Nutrient Deficiency
Yellow or clear new leaves → iron or micronutrient deficiency. Yellowing old leaves with green veins → magnesium deficiency. Holes in mature leaves → potassium deficiency. Slow growth + pale coloring → nitrogen deficiency. Purple undersides of leaves → phosphorus deficiency. Perform regular water changes (30-50% weekly) to prevent nutrient buildup in the substrate.