What is the ideal nitrate level for a betta fish tank?

In this blog we will discuss suitable levels of nitrate in bettas tank.This blog will help betta keepers to understand the correct nitrate levels and how to lower nitrates in bettas aquarium.


In this blog

  • What is the ideal nitrate level for a betta fish tank?
  • What is nitrate poisoning?
  • What are the symptoms of nitrate poisoning in betta fish?
  • How to reduce nitrate levels in bettas aquarium?
  • How to treat nitrate poisoning in an emergency situation in betta fish?
  • Is it possible for betta fish to recover from nitrate poisoning?
  • Do high nitrate levels increase algal growth in bettas tanks?
  • What is the difference between nitrate poisoning and nitrate shock?
  • Which nitrate testing kit is better?
  • Summary 
  • Frequently asked questions
  • Reference 

What is the ideal nitrate level for a betta fish tank?

The nitrate level in the betta tank should be 10-20 ppm. Nitrates are less toxic to fish than nitrites. Their accumulation occurs along with other water quality problems.

Nitrate levels in betta tank: <20 ppm.

What is nitrate poisoning?

Nitrate poisoning occurs when betta fish are exposed to gradually increasing levels of nitrate over any period of time when regular aquarium maintenance is not performed.

Overfeeding and overstocking bettas also greatly contributes to the slow rise of nitrate levels in a betta aquarium.

What are the symptoms of nitrate poisoning in betta fish?

Symptoms of nitrate poisoning in bettas are:

  • Poor color
  • Loss of appetite or weakened feeding response
  • Rapid gill movement
  • High respiratory rates
  • Lethargy 
  • Loss of balance 
  • Confusion
  • Curled body
  • Poor immune system
  • Abnormal swimming

Prolonged exposure to high nitrate levels can lead to bettas stress, stunted growth, organ damage and increased susceptibility to disease.

How to reduce nitrate levels in a bettas aquarium?

There are many ways to reduce and control nitrate levels in a betta tank:

Water changes in bettas aquarium

The easiest solution is to change the water. When you remove a volume of water from the aquarium, you remove all nitrates from that volume. So,change half the water and you’ve removed 50% of the nitrates.

Adding live plants in bettas aquarium

Add live plants to freshwater aquariums.Since live plants use nitrates for food, they help keep levels low.

  • Greenpro anubias 
  • Mainam dwarf hairgrass. 
  • SunGrow aquarium grass seeds
  • Live hornwort plant 
  • Aquatic arts marimo moss ball

Live plants extract nitrates from water & use them as fertilizers, helping to reduce nitrate levels in the aquarium.

Avoid overcrowding bettas tank/Keeping bettas in biggers and spacious tanks

Fish excrement leads to increased nitrate levels. Therefore, keeping overall fish populations relatively low helps prevent nitrate build-up. 

If you are considering a larger aquarium, try to resist the temptation to store more fish as the amount of nitrate-producing waste in the fish aquarium will inevitably increase.

Don’t overstock the aquarium. The more fish in the aquarium, the more waste it produces, and the more nitrates in the water.

Add cycled and efficient filters in bettas tank

In a new aquarium, if the aquarium is not fully cycled, nitrate levels can rise rapidly and you will need to check the levels periodically to monitor whether the cycle is successfully completed.

If you have an established aquarium, testing the water is an important part of your daily aquarium maintenance plan and you should always have a test kit on hand.

Hang on the back filters are outside the aquarium, which makes it easier to clean the filter material without disturbing the fish. 

It comes with biological, mechanical and chemical filtration.This filter keeps nitrates levels to minimum.

An internal power filter keeps the tank clean by providing three stages of filtration. It removes ammonia and nitrates from betta tanks.

The filters encourage the growth of tiny ecosystems of various microorganisms that help break down waste in the water.

Filters remove rotten organic matter, excess food, fish waste and other dangerous chemicals from the water. It also helps prevent nitrate stress in betta fish.

Dirty filters can also increase the ammonia levels in bettas tanks. Clean the aquarium filters at least once a month & change the carbon filter media regularly to control nitrate levels.

Add water conditioners in bettas tank

Seachem prime is the perfect water conditioner for betta fish as it detoxifies nitrates and dechlorinates water.

Using the right water conditioner removes nitrates from tap water. It also helps keep your fighting fish healthy by promoting the formation of their slime coat.

Avoid overfeeding bettas

Betta keepers should avoid overfeeding in order to keep the nitrate levels below 20 ppm.Overfeeding not only increases nitrate levels,but is also responsible for various issues related to digestive systems. 

Make sure you are feeding them on time and with utmost care.Feed them in moderate amounts and feed only what is digestible.Improper digestion leads to contamination of the aquarium because the betta fish produces more waste than usual.

Feed once or twice a day and fast one day a week to rest the fish’s digestive system.

Adding nitrate remover in bettas tank

Nitrate removers such as Algone gently remove nitrate from the aquarium and effectively prevent all common problems associated with high nitrate levels.

By reducing nitrate,Algone also removes cloudy & darkened aquarium water, restoring a crystal clear, shiny water column.

Algone removes contaminants & dissolved organic matter associated with high nitrate levels and other common aquarium problems.

Add aquarium salt or marine salt mix in bettas tank

  • Adding one tablespoon of salt per gallon of water will prevent nitrates from being absorbed from the bettas gills. 
  • You can use any mix of aquarium salt or sea salt or marine salt.
  • Do not use iodine-added salts.
  • Aquarium salt or marine salt mix maintains good health and provides bettas with the necessary electrolytes to achieve maximum color and vitality.
  • Do not overdose your betta aquarium with aquarium salts or marine salt mix

Increasing aeration in bettas tank

High levels of nitrates are also associated with oxygen-deficient water, which puts additional stress on the fish.

More water movement in aquariums always increases oxygen saturation. If necessary, add an additional filter or replace the existing filter with a more efficient one.

Other options are to use a powerhead filter, apply spray bars to the filter outlet, or use air stones.

How to treat nitrate poisoning in an emergency situation in betta fish?

In order to initially treat the nitrate poisoned betta fish, you should perform a major water change of up to 40%, which will dilute the contamination.

This is more of an emergency treatment and should be considered as a temporary solution to prevent or end betta fish mortality.

Is it possible for betta fish to recover from nitrate poisoning?

Betta fish can recover from toxic nitrate levels, but can become very sensitive to nitrates in the future.

In the most severe cases, poisoned betta fish can die within 24 hours. For this reason, you should take immediate action when you notice a problem and start treatment immediately.

Do high nitrate levels increase algal growth in bettas tanks?

If you are struggling to control algae in your tank, it could be due to high nitrate levels as they are related.

Nitrate levels as low as 10 ppm will encourage algae growth, and the algal blooms you see in new installations are often caused by poor aquarium circulation.

Plants use nitrate as an important food source; However, if the nitrate levels in the water rise too quickly, your plants will become covered in algae and suffocate and eventually die.

What is the difference between nitrate poisoning and nitrate shock?

Nitrate poisoning refers to a chronic problem, while nitrate shock refers to an acute problem that strikes quickly.

Nitrate poisoning in fish is caused by prolonged exposure, and nitrate shock occurs when fish are suddenly exposed to completely different levels of nitrate.Nitrate shock usually kills fish within 24 hours.

Which nitrate testing kit is better?

Nitrate test kits usually come in two forms: liquid or paper strips. Liquid test kits are generally preferred over paper strips as aquarium hobbyists find them more accurate. The paper strip test is easy to use & inexpensive.


  • Make sure to keep the nitrate levels in the bettas tank <20 ppm.
  • When the nitrate level in the water rises sharply, the plants in the tank are covered with algae.
  • Water changes are safe as they remove the nitrate from the system immediately and permanently.
  • High nitrate levels can become a problem in bettas tanks if regular water changes & other maintenance tasks are neglected.
  • Regular water changes with water with little or no nitrate will reduce the overall nitrate levels in the aquarium.
  • Add live plants to bettas tanks to lower the levels of nitrate. Bettas prefer densen vegetation in their tanks.
  • Never overfeed bettas, as it is one of the major reasons for nitrate pollution in bettas tanks.
  • Avoid overstocking bettas,as it is responsible for high nitrate levels in bettas tanks.
  • Use an efficient filtration system and water conditioner to remove nitrates from bettas tanks.
  • Use nitrate remover like Algone in bettas tank to remove nitrate from bettas tank.
  • Nitrate is less toxic to betta fish than ammonia and nitrite, but it can still kill them. This is well known as nitrate poisoning.
  • Monthly testing of betta aquarium water for nitrate levels is essential.

Frequently asked questions

What are the major reasons for the high nitrates level in bettas tanks?

Overfeeding and overcrowded bettas tanks are the major reasons for the high nitrates levels in bettas tanks.

Is nitrate more poisonous than nitrite levels to bettas?

Nitrate is not as toxic to bettas as nitrite. However,their accumulation usually occurs along with other water quality problems.

Do bettas die due to nitrate poisoning?

If bettas are suddenly exposed to very high levels of nitrates, they will typically die within 24 hours of exposure.

How long does it take for nitrate levels to drop? 

Nitrate levels will drop in 2-6 weeks.