Primary care for plant roots: specially produced clay balls, loaded with nutrients, for freshwater aquariums. Storage capacity for nutrients. No deficiency symptoms: important trace elements such as iron, minerals. Optimal promotion of plant growth means less algae growth. No phosphates and nitrates. Strong root formation in plants is a sign of high nutrient absorption through the roots. Package contents: 1 pack with 7 fertiliser balls. To use: depending on the size of the plant, press one to several balls into the root area every six months.