3 to 5 days. Potassium fulvic acid, a source of seaweed concentrate, can quickly take root. New roots will appear 3-5 days after application, and lateral roots and hairy roots will increase, making the leaves dark green, thickened, shiny, and strong. In addition to alginic acid, seaweed essence also contains nitrogen, an essential element for plants. Seaweed essence integrates plant nutrients, bioactive substances, and plant stress-resistance factors, making it an ideal full-function seaweed fertilizer.