Terralit 5000 gram bucket, Aqualine Buschke. Fresh water slow release soil fertilizer. Terralit is a slow release fertilizing material that provides an optimal nutrient supply for the aquatic plants via the aquarium substrate. Terralit is based on natural zeolite and is loaded with nutrients by a special manufacturing process. These nutrients can only be assimilated by the plant's roots, making over fertilization impossible. Terralit bonds nutrients, allowing for a rapid growth of the plants. 5000 g for 250 gallons