Seachem Flourish Advance is a plant supplement for aquariums that uses natural phytohormones, minerals, and nutrients to boost aquatic plant growth, stimulating strong roots and vigorous shoots while improving mineral absorption and disease resistance, and is safe for fish, shrimp, and all plants when used as directed. It works by mimicking natural plant growth regulators, leading to better establishment and overall health, with noticeable root growth first, followed by stem and leaf development, and can have a sweet/sour smell which is normal.