LAYOUT vol.008

English version of this article originally published in
Tropical Fish Hobbyist Magazine.

Adding Nutrients to an Aquatic Plant Layout

In past issues, I have introduced the way I create Nature Aquarium layouts. Are the plants in your aquarium growing well? Healthy aquatic plants become beautiful as they grow. To grow healthy plants, the most important thing is the substrate. Previously, I explained the way to build the substrate. In Nature Aquarium, a combination of Power Sand and Aqua Soil Amazonia are used as the base of the substrate primarily for the growth of aquatic plants. The substrate provides the basic nutrients for aquatic plants, such as nitrogen, phosphorous and other minerals, which aquatic plants absorb with their roots. They also absorb the nutrients that gradually dissolve in the water column through the surface of their leaves. In addition, some nutrients such as nitrogen and phosphorous are also supplied from the fish food or the feces of the fish kept in an aquarium. However, no matter how much nutrients the substrate holds, aquatic plants do not grow with the nutrient-rich substrate alone. Aquatic plants also need carbon to grow. In general, plants grow by taking in CO2 as a carbon source through photosynthesis. Therefore, the next important thing after the substrate is an environment in which aquatic plants can perform photosynthesis sufficiently. Adequately bright lighting must be provided and CO2 needs to be injected into the aquarium. Aquatic plants can grow well only when they perform photosynthesis and absorb nutrients from roots and leaf surfaces. Although nutrients are supplied from the substrate, they may not be well balanced or some elements may be missing. If no other nutrients are added, the aquatic plants often grow poorly and are eventually covered by algae.

Nitrogen and phosphorus are also nutrients required by algae, the archrival of an aquatic plant layout. The condition in which the body of water becomes enriched by dissolved nutrients is called eutrophication. When water becomes eutrophicated, algae tend to flourish. When fish are kept in an aquarium set up with Power Sand and Aqua Soil Amazonia, nitrogen and phosphorus may become excessive, but they are rarely depleted. Especially when an aquarium is just set up, the water becomes rich in nutrients and algae tend to proliferate, necessitating frequent water changes to remove them. In contrast to the nitrogen and phosphorus that can build up in an aquarium, potassium and trace elements can become limited. Potassium is a nutrient that aquatic plants require in a large amount along with nitrogen and phosphorus, and it is essential for healthy plant growth. The trace elements, such as iron and manganese, are the nutrients that are essential for plant growth but required in minute amounts. If it becomes limited, problems such as leaves losing color and developing holes arise even if aquatic plants are still growing in size.

In Nature Aquarium, Brighty K, which mainly consists of potassium, and Green Brighty Step 1, which is high in trace elements, are added daily. The Green Brighty Series offer Step 2, a trace element preparation rich in iron, and Step 3, a trace element preparation with potassium. These fertilizer preparations are selected according to the length of time that has passed since an aquatic plant layout is set up. As time passes, the environment in an aquarium changes, and the nutrient requirement of the aquatic plants changes as well. Normally, fertilization starts with Step 1, and by the time aquascape photographs are taken, aquascape data often shows the use of Step 2. By supplementing potassium and trace elements that tend to run short, the uptake of nutrients by aquatic plants becomes vigorous thus enabling the uptake of surplus nitrogen and phosphorus in large amounts. I recommend adding potassium and trace elements regularly every day since supplementing a nutrient that runs low results in suppressing the proliferation of algae.

Among many aquatic plants grown in an aquatic plant layout, the light demanding Riccia and stem plants show most vividly the difference in the way they grow in response to addition of a liquid fertilizer. Since these plants photosynthesize vigorously and grow fast, their nutrient uptake is likewise very prolific, and they absorb nutrients in the water through the surface of their leaves. Due to this reason, the effect of the addition of a liquid fertilizer shows up well in them. Most of these plants have bright green or red leaves, and the colors of their leaves become vivid with the addition of potassium and trace elements. Since the colors of the leaves come from the photosynthetic pigments, the colors of the leaves turning vivid indicate a vigorous photosynthesis. As a result, aquatic plants grow healthfully. In other words, beautiful aquatic plants mean healthy plants. The aquatic plant lacking a nutrient and losing the color of its leaves is not a healthy plant.

A strong indication of a nutrient deficiency in aquatic plants is yellowing or bleaching of leaves. Bleaching is a phenomenon known to occur due to an iron deficiency and shows up more often in Rotala rotundifolia (green), and Micranthemum umbrosum among stem plants, and Echinodorus grisebachii among rosette plants. Although the addition of a fertilizer high in iron such as Green Brighty Step 2 is effective for preventing bleaching; once the leaves bleach, it is difficult to make an improvement. When it starts to occur, increasing the concentration of iron in water temporarily with an additive containing a high amount of iron such as ECA can make a difference. However, excess iron in an aquarium encourages the growth of thread algae, turns water yellow, and the brown deposits of iron hydroxide form on the internal surfaces of the aquarium and on equipment. Since the brown deposits of iron hydroxide on aquarium equipment do not come off with alkaline cleaning solution, the equipment should be cleaned by soaking in an acidic cleaning solution. You can easily remove the deposits at home using vinegar.

The amount of a liquid fertilizer needs to be altered depending on the volume of aquatic plants in an aquarium. In the case of stem plants that grow well with an addition of a liquid fertilizer, the amount of the fertilizer given right after planting may be small. However, since they grow fast, they become dense in a short period of time. Therefore the amount of liquid fertilizer has to be doubled and tripled depending on their growth. In order to maintain stem plants, they need to be trimmed periodically. When trimmed, the amount of the liquid fertilizer needs to be reduced conversely. Such an adjustment of the amount must be done by observing the volume of aquatic plants and their condition.

Eusteralis stellata, which turned bright red with a supplementation of iron. Among trace elements, iron in particular plays an important role in the color of red stem plants.

Healthy Rotala macrandra. Stem plants grow well with a daily well-regulated addition of liquid supplements.

Gratiola sp. is a stem plant that changes the color of its leaves with an addition of liquid fertilizer

The terminal buds of bright green Rotala rotundifolia tend to breach if iron runs sort. Adding iron supplements, especially after trimming, prevents bleaching.

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