Ammonia Poisoning in Betta Fish – Causes and Prevention!

Ammonia poisoning is one of the most common causes of death in new betta tanks. Fortunately, if you catch it in time, it’s fairly easy to treat.

Here, we’re going to go over everything you need to know about recognizing, treating, and preventing ammonia poisoning in your betta tank.

Ammonia Poisoning in Betta Tank

Every tank has a delicate nitrogen cycle that must be kept in balance.

When fish excrete or exhale, they naturally produce ammonia that dissolves into the water.

Organic waste such as plants or food also produces ammonia as they decompose.

In a healthy tank, beneficial bacteria break down this ammonia into safer components such as nitrates and nitrites.

Ammonia levels should be as close to 0 ppm as possible.

If pH levels rise too high in your tank, it can disrupt the natural nitrogen cycle and lead to elevated ammonia levels.

When the ammonia concentration rises to an unsafe level, it can lead to ammonia poisoning in betta fish.

Also known as ammonia stress, nitrogen stress, or nitrogen poisoning, this condition can cause serious gill damage. It’s fatal in betta fish if left untreated.

Ammonia is colorless and odorless, making it nearly impossible to detect.

Instead, you have to monitor ammonia levels in your tank carefully and watch your fish for any signs of distress.

Common Causes of Ammonia Poisoning in Betta

There are many ways that ammonia can build up in your tank and harm your fish.

We’re going to go over some of the most common mistakes that can lead to ammonia poisoning in your fish.

An Improper Tank Setup

Ammonia poisoning is most common in new tanks.

Many betta owners make the mistake of filling their aquarium with tap water before introducing their fish.

However, many municipal water supplies get treated with harsh chemicals to make them potable.

Many cities use chloramine to help disinfect their drinking water.

While small amounts of chloramine might be safe for us to drink, it can be deadly for your fish.

When chloramine breaks apart, it can raise ammonia levels in your tank above 0 ppm and harm your fish.

Keeping Betta in an Unclean Tank

The decomposition of organic waste produces high levels of ammonia.

Plants and fish food are common culprits, but your betta itself can also produce ammonia waste during breathing and digestion.

Overfeeding often results in raised ammonia levels as uneaten food sits rotting in the tank bed.

Failing to clean your tank out regularly can also contribute to high ammonia levels.

Organic debris that builds up in the gravel, on decor, and in the water decomposes to produce dangerous byproducts that may harm your betta.

Dying Bacterial Colonies

Normally, beneficial bacteria take care of harmful ammonia in the water. It breaks it down into components that are safer for fish to digest.

Most tank owners build up colonies of good bacteria when they cycle their aquariums.

You can also introduce a populated substrate to build up from a small base colony.

Some more experienced owners introduce good bacteria by adding a filter pad rinsed in a separate healthy tank.

While it can take weeks to build up a healthy bacterial population, it can take only a few days to kill colonies.

Many betta medications that target bacterial infection don’t differentiate between different types of bacteria.

You can end up killing off your tank population, leading to a whole new host of health complications in your fish.

Bacterial colonies may also die due to fluctuating temperature and pH or because of a malfunctioning filtration system.

Whatever the reason, if the bacteria in your tank die, you’re likely to see ammonia levels rise to unsafe levels for your betta.

Also read: How to Get Beneficial Bacteria in Fish Aquarium?

Symptoms of Ammonia Poisoning in Betta

Ammonia has no color or smell, and so many owners don’t detect it in the water immediately.

One of the best ways to tell if your tank has high ammonia levels is to monitor your betta for symptoms.

Difficulty Breathing

High levels of ammonia in the water can burn the gills and make it difficult for fish to breathe.

You may notice your betta gasping for breath or rapid gill movements while swimming.

Betta may also search for cleaner water sources by lingering towards the top or bottom of your tank.

Panting in fish can also be a sign of other unfavorable environmental conditions. Poor water quality, heat, and certain chemicals can make breathing difficult.

Certain common illnesses such as ich also disrupt breathing in betta fish.

If you notice labored breathing, you should test your water to check if high ammonia levels are responsible.

It’s also a good idea to watch out for other secondary signs of poisoning.

Also read: Why Is Betta Fish Swimming Erratically?


In addition to damaging the gills, ammonia can also burn other sensitive areas of your fish.

The tissue around the eyes and anus is especially susceptible to damage.

Inflammation of sensitive areas such as these may indicate that your betta is suffering from ammonia poisoning.

It’s important to act fast, as fish can worsen rapidly at this stage. If left long enough, ammonia can cause irreparable tissue damage.

Color Changes

As their body takes on damage, you may notice changes in the coloration of your betta.

This is often the most noticeable symptom and one of the most surefire signs of ammonia poisoning.

Fish with ammonia poisoning often develop red, lilac, or purple around the gill area.

In advanced cases, you may even notice bleeding from the gills.

Some betta will also show red streaking along the body, especially in serious cases.

Keep in mind, however, that betta fish are also known to display red stress stripes.

These can look similar to ammonia-related streaking, so it’s a good idea to watch for additional symptoms.

Behavioral Changes

As any betta owner knows, this species of fish can have a voracious appetite. If you notice your betta refusing food, it could be a sign of ammonia poisoning.

Bettas with ammonia poisoning will also be much more lethargic than usual.

You may notice your fish isn’t swimming around as much as it normally does. In some cases, your betta may even rest towards the bottom of your tank.

Behavioral changes may also mean that something else is wrong with your fish, such as stress or illness.

The best way to tell if your fish’s symptoms are related to ammonia poisoning is to test your water.

You can find ammonia test strips and full-spectrum kits sold at most pet stores.

How Do I Treat Ammonia Poisoning in Betta Fish?

If you suspect high ammonia levels in your tank, you should treat your water as soon as possible to minimize damage to your betta fish.

Fortunately, there are several different ways that you can lower ammonia levels down to a safer level.

Use a Dedicated Detoxifier

You can quickly lower ammonia levels in your tank by using a chemical detoxifier.

It will bind loose ammonia molecules floating in your tank water, rendering them harmless to your betta.

While detoxifiers don’t technically remove ammonia from your tank, they can effectively lower the concentration to 0 ppm.

Detoxifiers also continue to work after treatment, helping to keep your tank healthy and balanced in the long term.

Add Ammonia Remover

Unlike detoxifying products, ammonia removers filter particles out of the water to reduce the concentration.

Ammonia removers often come in media form.

As water trickles through, the substrate attracts charged ammonia particles, removing them completely before returning filtered water to the tank.

Ammonia removers also make a good long-term solution for tank care.

They can help to keep your aquarium’s nitrate cycle in balance and ensure ammonia levels never get too high.

Change Out Your Tank Water

One of the quickest, cheapest, and easiest ways to reduce the ammonia concentration in your tank is to simply change the water.

Instead of changing all the water at once, it’s best to replace half your tank volume at a time. This ensures that you won’t shock the delicate ecosystem inside.

You may have to repeat the procedure each day for a few days before you see ammonia concentrations reach 0 ppm.

When changing out your tank, always remember to check the temperature and pH of the incoming water.

If it’s too hot or cold, your betta may suffer from potentially fatal temperature shock. S

imilarly, too high or low a pH can disrupt your tank’s nitrogen cycle and cause harm to your fish.

Preventing Ammonia Poisoning

The best way to treat ammonia poisoning is through prevention. You should always ensure that your tank is clean and the water properly filtered.

It’s also a good idea to introduce beneficial bacteria into new or deeply cleaned tanks.

You can do this by cycling your tank for a few weeks before introducing your betta.

It’s a good idea to perform regular ammonia tests to ensure that tank levels are safe.

This way, you can treat the issue before it causes any damage to your betta.

In Conclusion

Ammonia poisoning is a common issue in bettas, especially in new tanks.

It’s important that you keep an eye out for any signs of high ammonia levels in your tank.

As long as you catch the issue early on, ammonia poisoning is fairly easy to treat in bettas.

Through cleaning, care, and prevention, you can keep your tank healthy and ammonia-free.

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