Add 5 ml for each 100 Liters (27 gallons) once a week. Approximately 15 drops is 1ml, a bottle cap is 7ml. 125 ml is enough for 2,500 L(660 gallons)

Discus Minerals 4.22 Oz Concentrated Mineral Additive for Discus Fish – Improves Discus Health, Helps Reduce Stress and Replenish Protective Coat – Freshwater Aquarium Salt Treats 660 Gallons