How to reduce nitrates in freshwater aquarium

Nitrates are a composition of nitrogen and oxygen. They are formed when ammonia mixes with oxygenated water. It is easy to get confused between nitrates and nitrites however, they are distinct differences between both.

They are in fact two different types of compounds but are both produced by the breakdown of waste. Nitrite is highly toxic to fish. Nitrate isn’t as toxic but it will eventually affect the fish in your aquarium as the levels increase over time.

How are nitrates formed?

Nitrates are formed by an accumulation of factors. The combination of fish waste, festering plants, and leftover food that has begun to rot can lead to the formation of nitrates.

Nitrates also appear attractive to algae as they can be beneficial for their growth. While nitrate can be found in freshwater aquariums, it can also be present in tap water. 

The severity of the issue can differ depending on the type of aquarium. Although it can be present in freshwater aquariums, the levels tend to be higher in saltwater aquariums. In freshwater, nitrate levels should ideally remain below 20 mg/L. 

Reducing the nitrates

Nitrates are odorless and colorless which makes it difficult to detect the presence inside your aquarium. However, if left untreated high levels of nitrates can poison and kill fish. It can also lead to a reduction in oxygen levels in the water which can also be harmful and potentially deadly to your fish. 

Nitrates can be beneficial for aquatic plants. As their source of nutrition, nitrates can help the plants to grow faster. However, the nitrates can then become harmful to the plants if the levels continue to increase it can cause the plants to become deprived of oxygen too. 

Below we have identified some ways that you can reduce nitrates in your freshwater aquarium.

Feeding your fish the correct amount

This tends to be the leading cause of high nitrate levels in aquariums. If your fish is fed too much it is going to produce more waste as result. Feed your fish a varied, quality diet consisting of a healthy balance between frozen foods and fish flake foods.

Controlling the quantity of food that you feed your fish is crucial. More often than not, if your fish has been overfed it will then reject the food and as a result, this food will begin to rot inside the aquarium.

Nitrates or nitrites are a byproduct of this waste so over time if the levels of this waste continue to rise, the nitrate levels will too.  

Change the water

Changing the water and maintaining a clean tank are the easiest steps to take in reducing nitrates in your freshwater aquarium.

Of course, you will need to ensure that the water has a low nitrate level otherwise it isn’t going to make a significant change to the issue, water with a high nitrate level will worsen the issue.

Before changing the water, test your tank and the clean water for nitrates. The water that you use also needs to be the right temperature for your fish to thrive. When it comes to a freshwater fish tank, the temperature often depends on the species that you keep.

When you are changing the water inside of the aquarium, ensure that it is cleaned too. A clean tank isn’t going to hold waste and so fewer nitrates are going to be formed as a result. 

Use aquatic plants

Having live plants inside your aquarium can have multiple benefits. As well as reducing the growth of algae by absorbing their nutrients, a healthy aquatic plant can also absorb nitrates and other harmful chemicals that can be damaging to your freshwater fish.

If you have a severe issue with nitrates levels inside your freshwater aquarium, introduce some fast-growing plants. If they are kept under the right conditions, they can lead to a reduction in nitrate levels in a matter of days. 

Nitrate Remover Solution

The use of liquid solutions can help to remove nitrates from your aquarium. It is important to ensure that this liquid is used correctly to achieve the best results. If you are not able to carry out regular maintenance, you are likely to witness visible results through the use of a remover solution.

Another way of reducing nitrates is through the use of media. A media filter is a material that is used to filter and maintain the quality of water. In aquariums, sand tends to be the most common type of filter used.

A bed of sand inside your aquarium serves the purpose of removing harmful pollutants and chemicals. Nitrate removers are available in two forms of filter media. These are disposable media or permanent media. 

How long can fish survive with high nitrate?

Nitrate levels that exceed 80ppm can be toxic for your fish. As mentioned nitrate can be hard to detect as it isn’t visible. There are signs that may indicate that there are high levels of nitrates inside your aquarium.

You may notice a difference in your fish or fast algae growth. Sudden exposure to high nitrate levels can cause your fish to die quite soon after. A gradual build-up of nitrates in the water can lead to disease.

Final Thoughts

Whilst nitrates aren’t considered to be as harmful as nitrites if left untreated over time nitrates can cause your fish to become ill and in some cases, it can result in death if they are exposed to high levels suddenly.

There are steps that you can take to reduce the levels of nitrates. Maintaining a clean tank is important in removing the build-up of waste which attracts nitrates. Also, ensure that your fish are fed the correct amount as overfeeding is deemed to be the leading cause of high nitrate levels.

You may opt to use a liquid remover or media filter. You may witness more immediate effects with some methods more than others. Some steps may also be more effective long term than others.