JBL 7+13 Balls are pressed fertilizing pellets, enriched by a special process with all the nutrients vital for aquatic plants, especially iron and trace elements. The nutrients are released slowly, providing a very favourable depot effect. The ball shape permits the convenient use in existing freshwater-aquariums. Specially suitable for the specific nutrient supply or post-fertilization of aquatic plants which mainly absorb their nutrients through the roots, such as echinodori, cryptocory-nae, and others.JBL 7+13 Balls are particularly suitable for revitalizing depleted substrate in an aquarium, renewing the regulative function of the ground covering material, without the need to empty the aquarium.JBL 7+13 Balls+ for long-term root fertilising in an established aquarium+ does not contain phosphates and nitrates+ contains iron and minerals in a form readily accessible for plants to absorb through the rootsUse of JBL 7+13 BallsDepending on size of the aquatic plant, press one or more ba