Nature Aquarium’s liquid fertilizers have been developed with the idea of supplementing deficient nutrients to allow excessive nutrients to be absorbed. However, there is an issue in that nutrients required for aquatic plants vary with the condition of the aquarium including the growth stage of aquatic plants. For example, an aquarium with dense sun plants, such as Riccia which actively performs photosynthesis, requires more potassium to have the effect of promoting photosynthesis. On the other hand, stern plants require many different types of trace elements for the development of new buds and also a lot of iron which is essential for the formation of pigments conducive to brighter leaf colors.
The newly planted aquatic plants need to form new buds and develop leaves and stems to grow. To achieve this, nitrogen, phosphorus, potassium and trace elements including magnesium and manganese are essential. In particular, lack of each trace element may result in curled buds or twisted leaves due to poor growth. To avoid these problems, it is ideal to supply each type of trace element in good balance during the new bud stage, i.e., from the initial stage up to the third month. Meanwhile in the plant growth stage when the aquatic plants grow vigorously and develop many leaves (3 months up to 1 year after the aquarium setup), the aquatic plants need to form plentiful photosynthetic pigments and also other pigments to regulate the progress of photosynthesis.
To achieve this, a large amount of iron is especially required. Once the pigments are actively formed as a result of iron supply, the aquatic plants display a strong green color and, at the same time, the color of red stern plants is enhanced in the bright area which has abundant light. Later on, the growth of aquatic plants will become less vigorous and the stern plants that have gone through repeated trimming will be around one year old after planting. An effective way to slow down the aging of aquatic plants is to supply an increased amount of potassium. This is the reason why potassium is to be dosed separately
Excessive nitrogen and phosphorus in the aquarium need to be removed by such measures as water change to avoid algae infestation. When the aquatic plants are not yet blooming, they are unable to absorb such excessive amounts. However, once the aquatic plants have grown healthily and densely, nitrogen and phosphorus are hardly detected even without frequent water changes. Even if fish are present in the tank and fed adequately everyday, the level of these nutrients is extremely low as long as the aquatic plants are dense enough.
This shows that aquatic plants have excellent water purification ability. In order to promote this ability, we should understand how aquatic plants absorb nutrients and then apply the acquired knowledge effectively. Unlike terrestrial plants that absorb water and nutrients from their roots, aquatic plants can absorb nutrients through their surface including leaves and stems. Aquatic plants have developed this characteristic so that they are able to absorb nutrient salts dissolved in water in an environment where they are always immersed in the water. Among the aquatic plants, Cryptocoryne and Echinodorus are the species that actively absorb nutrients from the roots, while stem plants absorb nutrients more from the leaf surface. For stem plants, the roots are merely an organ to anchor the plant body to the substrate. Epiphytic plants such as ferns, moss and Anubias also absorb nutrients directly from the water. Therefore for these plants, the immediate effect of nutrient supplementation can be expected by directly adding liquid fertilizer to the water.
Nevertheless, not all the liquid fertilizers are effective. For example, if liquid fertilizer designed for terrestrial plants is added directly to a tank, the tank will soon be covered with algae. Meanwhile the aquarium with fish has a tendency to experience excessive nitrogen and phosphorus but lack of potassium and trace elements. There is a widely known principle called “The Law of the Minimum” which states that the growth of a plant is limited by the particular nutrient least available in relation to the total requirements of the plant. This principle also applies to aquatic plants in an aquarium tank and, if this Law of the Minimum is applied in reverse, more amounts of excessive nutrients will be absorbed by supplementing the nutrients that are lacking.
This is Nature Aquarium’s basic concept of nutrient supplementation. Under this concept, liquid fertilizer containing potassium and trace elements as major ingredients is added to Nature Aquarium daily so that nitrogen and phosphorus that tend to be excessive will be absorbed by the aquatic plants. It can be said that this method is very reasonable as it promotes the healthy growth of aquatic plants and at the same time deters algae infestation.
Whether in nature or in the aquarium, aquatic plants grow through photosynthesis. They absorb CO2 for this essential process but from the viewpoint of nutrients, CO2 is merely a carbon source. Besides carbon, aquatic plants need nitrogen, phosphorus, potassium as well as trace elements such as iron and manganese for healthy growth. If these plants are given an opportunity for photosynthesis only, they will grow big but may show some growth disorder including thin, poor stems and leaves, yellowed leaves and bleached new buds. The cause of these symptoms is lack of nutrients.
Nutrients are the source of amino acid, nucleic acid and chlorophyll, crucial to the healthy development of the stems and leaves of aquatic plants. In nature, these nutrients are supplied in the form of nutrient salts dissolved in river water or circulating in lakes and ponds. In the aquarium tank, however, a certain amount of minerals supplied through the change of tank water but it is not sufficient in terms of both types and amount. Tap water contains a relatively high level of calcium and magnesium but no iron and manganese in most cases. Even if these elements are contained in tap water, they are most likely to be combined with other substances and become unusable to aquatic plants. For nitrogen, phosphorus and potassium which are actively absorbed by aquatic plants, it is difficult to supplement the required amounts to a Nature Aquarium which has lush plants just by water change. In nature, a sufficient amount of these nutrients is supplied by dissolution of organic matters such as the feces of living organisms and decomposed plants, but they are usually removed from tap water through the purification process.
For Nature Aquarium, Aquarium Soil containing nutrients and organic matters are used for the substrate for the purpose of nutrient supplementation to aquatic plants. During the initial stage, mainly nitrogen and minerals are released into the water from the substrate but the amount will be lower once the substrate is covered with thriving aquatic plants. Another issue is insufficient supply of phosphorus and potassium in contrast to sufficient, or at times excessive, amounts of nitrogen in the water. Another source of nutrients in the aquarium is fish feces and unconsumed fish foods. These are a source of nitrogen and phosphorus but cannot be relied on as an effective source of potassium and trace elements. As a result, Nature Aquarium in the initial stage is prone to excessive nitrogen and phosphorus, on the one hand, and lack of potassium and trace elements, on the other. Excessive nitrogen and phosphorus contribute to the growth of algae, which affects the appearance of the layout and hinders the healthy growth of aquatic plants.
