An excellent source of important trace elements for aquarium plants. Seachem Flourish Trace replenishes important trace elements that can be rapidly depleted by various chemical processes and natural plant growth. Flourish Trace accurately supplies the trace elements truly needed for continued lush growth of freshwater plants. Flourish Trace does not add random trace elements to ensure proper aquarium plant health and growth. Allows for more frequent dosing without build up of more slowly used components often associated with broad-spectrum supplement use. Dosage: One capful for every 20 gallons twice a week. 250 ml treats 50 gallons for 2-4 months.