High nitrates in planted aquariums are usually caused by overfeeding, overstocking, insufficient water changes, or inadequate filtration. Nitrates are the end product of the nitrogen cycle, which converts ammonia and nitrite from fish waste and decaying organic matter into less harmful nitrates. However, nitrates can still be harmful to fish and plants if they accumulate to high levels, as they can cause algae growth, stress, disease, and even death.
In this article, we will explain how to prevent and reduce high nitrates in planted aquariums, and how to test and monitor the nitrate levels in your tank. We will also discuss the benefits of having a balanced and healthy planted aquarium, and how plants can help lower nitrates naturally.
The best way to prevent high nitrates in planted aquariums is to avoid the common causes of nitrate buildup, such as overfeeding, overstocking, insufficient water changes, or inadequate filtration. Here are some tips to follow:
Feed your fish only as much as they can eat in a few minutes, and remove any uneaten food from the tank. Overfeeding can lead to excess waste and organic matter, which can increase the ammonia and nitrite levels, and eventually the nitrate levels in your tank.
Stock your tank with the appropriate number and size of fish for your tank size and filtration capacity. Overstocking can also result in more waste and organic matter, and higher bioload, which can overwhelm your filter and cause nitrate spikes. A general rule of thumb is to have one inch of fish per gallon of water, but this can vary depending on the species and behavior of your fish.
Perform regular water changes to dilute the nitrates and other pollutants in your tank. Water changes are essential for maintaining good water quality and balance in your tank, as they remove the excess nitrates and replenish the minerals and trace elements that your fish and plants need. You should aim to change 25% to 50% of your water every week, depending on your tank size, stocking level, and nitrate level.
Use a good filter that can handle the bioload of your tank, and clean it regularly. A filter is responsible for removing the solid and dissolved waste from your tank, and hosting the beneficial bacteria that break down ammonia and nitrite into nitrates. You should choose a filter that has enough mechanical, biological, and chemical filtration media for your tank, and clean it every month or so, without disturbing the beneficial bacteria. You should also avoid over-cleaning your filter, as this can reduce the bacterial population and impair the nitrogen cycle.
If you already have high nitrates in your planted aquarium, you can take some steps to reduce them and restore the health of your tank. Here are some methods to lower nitrates in your tank:
Perform a large water change to quickly lower the nitrate level. If your nitrate level is above 40 ppm (parts per million), you should do a 50% to 75% water change as soon as possible, and then repeat it every few days until the nitrate level is below 20 ppm. You should always use dechlorinated water that matches the temperature and pH of your tank water, and add a water conditioner that can detoxify nitrates, such as Seachem Prime.
Add more plants to your tank to consume the nitrates and improve the water quality. Plants are natural nitrate reducers, as they use nitrates as a source of nitrogen for their growth and photosynthesis. By adding more plants to your tank, you can create a natural balance between the nitrogen producers (fish) and consumers (plants), and reduce the need for water changes and filtration. You should choose plants that are suitable for your tank size, lighting, substrate, and fish compatibility, and provide them with adequate nutrients and CO2. Some of the best plants for lowering nitrates are fast-growing plants, such as hornwort, duckweed, water lettuce, water sprite, anacharis, and cabomba.
Use a nitrate remover product or media to chemically remove the nitrates from your tank. Nitrate removers are products or media that can bind or absorb the nitrates from your tank water, and make them unavailable for algae and bacteria. You can use nitrate removers as a temporary solution to lower high nitrates, or as a supplement to water changes and plants. You should follow the instructions and dosage of the product or media, and monitor the nitrate level regularly. Some of the common nitrate removers are Seachem Denitrate, API Nitra-Zorb, and Poly-Filter.
How to Test and Monitor the Nitrate Levels in Your Tank
Testing and monitoring the nitrate levels in your tank is important for maintaining a healthy and balanced planted aquarium. High nitrates can be hard to detect by the naked eye, as they do not cause any obvious changes in the water color or clarity. However, high nitrates can have negative effects on your fish and plants, such as:
Algae growth: High nitrates can fuel the growth of algae, which can compete with your plants for nutrients and light, and make your tank look unsightly and dirty. Algae can also reduce the oxygen level in your tank, and release toxins that can harm your fish and plants.
Stress: High nitrates can cause stress to your fish, as they can irritate their gills and skin, and affect their immune system and metabolism. Stress can make your fish more susceptible to diseases and infections, and reduce their lifespan and growth.
Death: High nitrates can be lethal to your fish and plants, especially if they are exposed to them for a long time, or if they are combined with other factors, such as high temperature, low oxygen, or ammonia and nitrite spikes. High nitrates can cause nitrate poisoning, which can result in symptoms such as lethargy, loss of appetite, gasping, redness, and death.
To test and monitor the nitrate levels in your tank, you should use a reliable and accurate test kit, such as the API Freshwater Master Test Kit, which can measure the ammonia, nitrite, nitrate, and pH levels in your tank. You should test your tank water at least once a week, or more often if you have a new or unstable tank, or if you notice any signs of high nitrates, such as algae growth, fish stress, or plant deterioration. You should also test your tap water, as it may contain nitrates from the source or the pipes, and affect your tank water quality.
The ideal nitrate level for a planted aquarium is between 5 and 20 ppm, depending on the type and number of plants and fish you have in your tank. Some plants and fish can tolerate higher or lower nitrate levels, but you should always aim to keep the nitrate level as low and stable as possible, to ensure the health and well-being of your tank inhabitants.
Conclusion
High nitrates in planted aquariums are a common and serious problem that can affect the health and appearance of your tank. High nitrates are usually caused by overfeeding, overstocking, insufficient water changes, or inadequate filtration, and can lead to algae growth, stress, disease, and death. To prevent and reduce high nitrates in planted aquariums, you should follow these steps:
Feed your fish only as much as they can eat in a few minutes, and remove any uneaten food from the tank.
Stock your tank with the appropriate number and size of fish for your tank size and filtration capacity.
Perform regular water changes to dilute the nitrates and other pollutants in your tank.
Use a good filter that can handle the bioload of your tank, and clean it regularly.
Add more plants to your tank to consume the nitrates and improve the water quality.
Use a nitrate remover product or media to chemically remove the nitrates from your tank.
Test and monitor the nitrate levels in your tank using a reliable and accurate test kit.
By following these steps, you can create a balanced and healthy planted aquarium, where your fish and plants can thrive and flourish. We hope you found this article helpful and informative, and we wish you the best of luck with your planted aquarium. Thank you for reading!
