Tropica Plant Growth Premium Fertiliser contains the most important nutrients for healthy and sustained aquarium plant growth. Premium Fertiliser does not however contain nitrogen (N) or phosphorus (P). Tropica Premium Fertiliser therefore supplies the nutrients plants easily run out of and which plants ideally absorb via the leaves. These are the nutrients which are supplied via fish excrement and food remnants. We therefore recommend Premium Fertiliser for aquariums with few plants and a relatively large number of fish.Use and Dosage of Tropica Tropica Plant Growth Premium Fertiliser:Tropica Plant Growth Premium Fertiliser is added each week when changing the water. A flask is used to ensure an accurate dosage. We recommend 5 ml per 50 L water per week, but recommend that this is set in accordance with plant requirements. For example, light leaves often indicate lack of nutrition, but can also be due to poor growth.Tropica Plant Growth Premium Fertiliser is well suited to be use with