Tropica Plant Growth Premium Fertiliser is specially formulated to promote healthy and sustained growth in aquarium plants. It provides the essential nutrients plants easily run out of which are typically absorbed through the leaves (nutrients supplied via fish waste and uneaten food). Premium Fertiliser contains iron and all other essential trace elements required for optimal plant growth. Although not a medication, regular dosing of Premium Fertiliser can also help rejuviate discolored and withering leaves. Does not contain nitrogen or phosphorus. Recommended for aquariums with few plants and a relatively large number of fish. A minimum 25% of the aquarium water should be changed every second week when dosing this product. 300 ml bottle treats up to 660 gallons.