Premium Fertiliser is added every week when changing the water. The pump bottle dispenses 1,2 mL per push. We recommend 6 mL (5 pumps per 50 L water per week), but recommend that this is set in accordance with plant requirements. For example, pale leaves often indicate lack of nutrition, but can also be due to poor growth. Echinodorus bleheri is a typical example of lack of micro-nutrients. Regular dosing with Premium Fertiliser can restore green and luxuriant leaves. Note, however, that Premium Fertiliser is a fertiliser and not a medicine for dying plants. It is recommended that minimum 25% of the aquarium water is changed every second week. If undesirable algae growth does occur, then we recommend increasing water change frequency (up to 50%) and planting additional rapid growth waterplants such as Hygrophila, Vallisneria and Egeria.