The Best Way To Remove Nitrate From A Fish Tank

Last Updated on April 29, 2022 by Marco C.

Do you know how to remove nitrate from a fish tank? This article will teach you some key techniques to perform this important task! 

Almost all fish tanks will contain Nitrites and Ammonia.  These are forms of Nitrogen that are generated by organic material breaking down inside of your tank. When the Nitrite levels get too high, the health of your whole system is in danger.  

It is important to be able to remove nitrate from a fish tank when this happens.  Keep in mind that this is all naturally occurring.  This means that it is basically unavoidable.  Nitrates will definitely form in your tank. 

It is your task to make sure you study water chemistry and know-how to reduce nitrate levels when they get too high.  Lucky for you, we have compiled all the key information that you need to know. 

Not only will we teach you how to remove nitrate from a fish tank, but we will also overview how to avoid nitrates from getting too high in your tank.

After reading this article, you should be confident in handling any nitrate problem that comes your way.  

Keep reading to become an expert on this topic!

Lowering Nitrates In An Aquarium

An aquarium system consists of a tank, water, plants, and fish.  This tank is a closed system.  No water enters or exits the tank naturally. 

Tank owners are required to maintain the water to make sure it stays in a healthy condition for their fish.  This is why you may need to lower the nitrates in your tank.  

If your tank water is not maintained, organic materials will build up, causing your fish to die.  This is one of the main reasons a fish tank needs a filter.  Water from your tank passes through the filter and removes excess debris.  There are different kinds of filters.

One filter is called a biological filter.  This is a great filter to remove nitrate from your fish tank.  Once the biological filter is established, it grows special bacteria.

biological filter

Learn more about: How To Make A Biofilter For Aquaponics?

These bacterias consume and digest harmful nitrates in your tank.  Whenever any organic material is in your tank it follows a certain biological path.

First, this material starts as Ammonia.  At this point, it is considered toxic for your fish and Naturally, the ammonia turns into Nitrite.  This is also harmful to your tank’s ecosystem.

Finally, nitrates are converted by bacteria into nitrate.  Nitrates are actually a usable form of nitrogen for your plants.

This means that it is beneficial for your plants because they need nitrogen to grow.  However, you still do not want there to be an overabundance of nitrate in your tank.  If you do not have enough plants to use up all the nitrate, you can have a problem.  

A good nitrate level to aim for is between 30ppm to 40ppm.

Quickest Ways To Reduce Nitrates In A Freshwater Tank

There are some simple ways to remove and reduce nitrates from your fish tank.  First off, you need to make sure you are not fueling the problem. 

The biggest source of a buildup of nitrites and nitrates is because there is an excess of organic debris in your tank.  So where does all this organic matter come from?  Typically, it is from the food that you feed to your fish.

Quickest Ways To Reduce Nitrates In A Freshwater Tank

Do not overfeed your fish.  Fish will only eat until they are full.  Everything else will simply break down in your tank.  

This means it will start the process of turning into nitrites and nitrates.  If you do not put too much food into your ecosystem, you will avoid this problem overall.

Another way to avoid the buildup of nitrites is to keep your water clean.  The best way to do this is to do frequent water changes.  Change your water once a week at least.  

Keep in mind that tap water naturally contains some nitrates.  The best way to understand your tank’s water chemistry is to test your ammonia levels.  Ammonia test kits will help you gauge if your levels are reaching dangerous levels. 

According to New Mexico State University, “As a general rule, start-up systems should be tested daily so that adjustments can be made quickly when needed.” So if your fish tank is new, be sure to pay closer attention to it.  Once your tank is established you can test it on a weekly basis. 

You can also put more plants in your system.  Plants love to use nitrate to grow.  However, the best way is to avoid causing the problem in the first place!

Now you should understand the ways to remove nitrate from a fish tank. Always aim to keep your ecosystem balanced.  That is the best way to provide a good life for your fish.

Feel free to comment and ask questions below!

Read more about: Your Step By Step Guide To Unionized Ammonia Calculation


How do you lower nitrates in an aquarium?

You can lower nitrates in your aquarium by adding more aquatic plants. Plants absorb and use nitrates to grow. The more plants in your system, the more nitrates are removed. However, you need to keep your fish tank clean overall. If you have a dirty fish tank and a lot of plants, it will not help solve your nitrate problem.

What is the fastest way to lower nitrites in a freshwater aquarium?

The fastest way to lower nitrates in your aquarium is to remove the polluted water and replace it with clean, fresh water. If you have a serious problem, remove 100% of your water. Otherwise, you can aim to change out between 25-35% of the water on a weekly basis.

How to remove nitrates from fish tank?

Remove nitrates from your fish tank by adding plants to your tank or changing your tank’s water. Always be aware of your tap water source to make sure it does not have chlorine.

What is a good nitrate remover?

The best remover of nitrate inside a fish tank is plants. Plants need nitrogen to develop their leaves. They will absorb nitrate and use it to grow. Of course, avoid over planting your fish tank because it will cause overcrowding of your tank. If you have a serious nitrate problem, you need to change your tank water!