Macronutrients - Nitrates
We've talked about nitrates before, but do we truly understand their function for plants? Let's explore the importance of nitrates for aquarium plants.
Nitrates are a vital source of nitrogen, a fundamental nutrient for aquatic plants. They are generated as a result of the nitrogen cycle in the aquarium, which involves the decomposition of organic waste, such as food and debris, by microorganisms present in the substrate, filter, and aquarium water.
Aquarium plants use nitrogen to synthesize amino acids, which are essential in building proteins. These proteins are crucial for plant growth, contributing to biological functions such as chlorophyll production, maintenance of new tissues, and regulation of metabolism.
In the absence of adequate nitrates, aquarium plants may exhibit slow growth, yellowing leaves, and reduced resistance to disease and pests. Nitrogen deficiency can also trigger a chemical imbalance in the aquarium, increasing the pH and making the environment hostile to fish and other aquarium creatures.
Liquid fertilization and nitrates
Liquid fertilization is a common practice for providing additional nutrients to aquarium plants. It consists of adding liquid solutions containing a mixture of nutrients, including nitrates, directly to the aquarium water. This provides an additional nutritional supply to the plants, beyond what is produced by the nitrogen cycle. Liquid fertilizers contain nitrates in varying concentrations depending on the brand and type of product. It is crucial to carefully follow the manufacturer's instructions when adding liquid fertilizers to your aquarium to avoid overloading the plants with excess nutrients, which can result in excessive algae growth.
Applying liquid fertilizers containing nitrate can significantly improve the health and appearance of aquarium plants. It promotes vigorous and healthy growth, increases oxygen production, and improves the water quality of the aquarium.
However, it is crucial to remember that high nitrate levels can be harmful to aquarium plants. Excessive concentrations can trigger excessive algae growth, competing with plants for nutrients and light. Furthermore, high nitrate levels can be toxic to fish and other aquarium inhabitants, causing damage to gills and other organs. Therefore, it is crucial to maintain a proper balance of nutrients and regularly monitor nitrate levels in the aquarium.
Other sources of nitrate in an aquarium include tap water and fish food. Overfeeding fish can contribute to increased nitrate levels in the aquarium, so it is important to control the amount of food given to avoid excess nutrients and not overcrowd the aquarium with too many fish for the available water volume.
Ideal nitrate levels generally range from 5-25 ppm, depending on the amount of plants, CO2 injection, and other factors. Levels above 75/80 ppm are considered toxic to fish. However, nitrates alone are not the only cause of algae blooms; the overall balance of the environment is essential. Having 40 ppm of nitrates is pointless if phosphate or potassium levels are low, as these will become the limiting factor, or if there are no plants competing with the algae.
Healthy and robust plants inhibit algae growth, and it is common to observe densely planted aquariums without algae and problems, unlike aquariums with few plants, where the margin for error is smaller when plants are not the dominant feature of the aquarium.
