Betta Ammonia Poisoning – Symptoms, Causes, & Treatments

    Betta ammonia poisoning

    Betta ammonia poisoning is a preventable but common cause of death in these fish. Ammonia is a toxic compound that comes from the breakdown of proteins in a fish’s body. As well as the decay of leftover food and other sources of organic matter. What can be done to treat betta ammonia poisoning?

    You will need to first measure ammonia levels using an ammonia test kit. Next, perform water changes to quickly reduce its concentration. Preventative measures include adding plants, feeding less, and performing aquarium maintenance on a regular schedule.

    What Is Betta Ammonia Poisoning?

    Bettas are famous for being very hardy fish. They are found in small bodies of water in polluted conditions that would kill other fish.

    But even they can die from too much biological waste. Ammonia is the most toxic waste product that fish produce. In nature, even a small stream or pond has far more water volume than a betta tank.

    Any ammonia released is diluted immediately. But in a home aquarium, small amounts of ammonia concentrate easily. Causing ammonia poisoning in a very short time.

    How Is Ammonia Removed From Fish Tank Water?

    Ammonia spikes are rarely an issue in aquariums that are fully cycled. Cycling happens when you have a healthy set of nitrifying bacteria to process fish waste.

    These beneficial bacteria live in your filter, the tank water, the gravel…Anywhere they can find space to call home. There are two sets; the first are the ammonia detoxifiers. These organisms take ammonia molecules (NH3+) and eat them, releasing nitrite (NO2-) as waste.

    Nitrite is less toxic than ammonia but it can still cause poisoning in betta fish. Fortunately, a second bacteria colony eats nitrite, reducing it further into nitrate (NO3-).

    Nitrate is much less toxic and betta fish are very resistant to it. Levels of 10-20 parts per million are healthy and signs of stress don’t arise until 30 ppm. Nitrate does not leave the system unless live plants use it as fertilizer. Or you remove it during water changes.

    The nitrogen cycle requires a bit of chemistry to understand it. Take a moment to watch this explainer video on the topic if you hope to learn more!

    YouTube player

    Main Symptoms Of Betta Ammonia Poisoning

    Betta ammonia poisoning symptoms

    Here are the most common symptoms of ammonia poisoning in betta fish:

    • Listless behavior
    • Inflamed fish’s gills
    • Color changes
    • Hanging near the surface
    • Loss of appetite

    Listless Behavior

    A betta fish is behaving in a listless fashion when it loses interest in active exploration. A healthy betta spends much of its time poking around the fish tank, looking for food or at other fish. They dash to the surface for air, fight with their exercise mirrors, and build bubble nests.

    Listless bettas do none of these things. The fish just sits around, swimming slowly. This is also a symptom of other disorders besides ammonia poisoning.

    These include cold water temperatures and disease. But behavioral changes are always an invitation for you to look deeper.

    Inflamed Gills

    Aquarium fish’s gills serve multiple purposes. They are not only oxygen exchange zones. The gills also release waste into the water, including ammonia. In a wild ecosystem or a tank with a healthy nitrogen cycle, this ammonia never builds up.

    But if your tank water has too much ammonia, the toxin starts to interfere with gill function. Fish gills may even turn bright red or start bleeding from ammonia burns. Red streaks in the eyes and fins are another common sign.

    Color Changes

    Fish use their colors and patterns to signal to each other and to you. By noticing when your fish change color, you can infer a lot about their moods and health. Betta ammonia poisoning can cause pale colors and stress stripes to arise.

    If the ammonia levels in your aquarium water stay high for too long, fish can also get ammonia burns. These burns are discolored patches on the skin or fins that are often black in color.

    An ammonia burn can be temporary or permanent. It depends on how severe and long-lasting the rising ammonia levels were.

    Hanging Near The Surface

    As gill function gets compromised by ammonia poisoning, your betta fish will start spending more time near the surface. It has less energy for swimming around, for one.

    A poorly circulated and oxygenated betta fish tank is especially prone to developing high ammonia levels. So the betta fish will remain near the surface, where oxygen levels are highest. Ensuring it has to do little swimming to keep breathing properly.

    Loss Of Appetite

    All fish keepers know that betta fish rarely refuse a good meal. If your bettas stop eating then it’s an immediate sign to check in. Fish ammonia poisoning causes them to lose their appetite due to stress. They eat will very slowly, or not at all. Ammonia will kill a healthy fish faster than starvation, however.

    Main Causes Of Betta Ammonia Poisoning

    Are you are seeing symptoms of ammonia poisoning in a betta fish? Then let’s take a moment to consider some of the main causes of the issue.

    Not Doing Regular Water Changes

    Even in a fully cycled aquarium, ammonia buildup can occur. Your beneficial bacteria colonies can only consume so much excess ammonia. Water changes help take care of the rest.

    If you put off doing water changes, the measurable ammonia present is sure to rise. It’s more common to see nitrite and nitrate spikes due to a lack of water changes. But ammonia poisoning is also a possibility.

    Doing a water change is always a good idea, even if you aren’t sure what the problem is. Water changes reduce the concentration of any pollutants. They also add fresh, oxygenated water to the tank, giving your fish a better chance of fighting off any diseases or poisons.

    Not Having A Filtration System

    An aquarium filtration system is just as important as doing water changes. Filters provide a proper living space for your beneficial bacteria. They also contain chambers for activated carbon and other filter media used to polish your tank water.

    Sometimes I see betta tanks without a filter. Some setups even suggest using a plant, such as a spider plant, as the “filter.” These systems are always a bad idea. Water left unfiltered will stagnate.

    Fish waste and uneaten food will decay into ammonia and other toxic byproducts. Even a tough betta fish will not truly thrive without a filtration system.

    Leftover Food Decay

    There are more sources of tank pollutants than fish waste. Uneaten food is a major source of ammonia buildup in aquarium water.

    Food that goes uneaten will collect under bits of gravel and in other hard to reach places. There, bacteria colonies start feeding on it. Releasing ammonia into your tank water.

    When feeding your fish, you should always aim for all of the food being eaten. With no leftover food remaining, unless there are bottom feeders sure to clean it up.

    Too Many Fish

    One betta fish does not release too much ammonia. But a community tank full of other fish will release ammonia constantly. How familiar are you with good stocking rules for fish tanks?

    Overcrowded tanks may look pretty but they come with many problems. Not only do all of these fish produce ammonia; they also consume more oxygen and food. Which means more aeration and more water changes need to be done. The filter needs to be larger as well.

    I always recommend under-stocking fish tanks rather than adding as many fish as possible. Giving fish more space ensures the ammonia level stays low.

    Plus the fish have room to form territories and display other natural behaviors that would be impossible in a crowded community tank!

    A Hidden Dead Fish

    Any organic matter left to rot can cause ammonia poisoning in betta if not removed. And a dead tank mate is one of the worst sources of toxic compounds.

    Much like leftover food, a dead fish is a huge source of proteins. Nitrogen is a major building block of proteins. So as these decay, they release a constant stream of ammonia.

    When fish are dying they tend to hide when the end draws near. And if the dead fish is one of several schooling fish, you may not realize one has died for a few days.

    This is why testing your water weekly is important. A sudden rise in testable ammonia is a sign to look closer. Plus, a fish dying may indicate disease or some other issue to consider.

    How To Treat A Betta With Ammonia Poisoning


    Ammonia poisoning betta cure

    Ammonia poisoning is deadly if not treated soon enough. But it is also one of the easier aquarium water problems to reverse! Here are the supplies you need. As well as instructions on how to proceed!

    Supplies Needed

    Using your ammonia test kit, sample your fish tank water to get a reading on the precise amount of ammonia present. I recommend using a fluid test kit rather than dry testing strips.

    Dry testing strips are convenient and faster. While fluid ammonia tests are more time consuming to use. But fluid tests are also much more accurate.

    Test strips gives you a colored concentration “range.” They are good for measuring whether there is any testable ammonia or not. But we need accuracy when dealing with ammonia poisoning to know what steps to take. A fluid kit gives you exact numbers if parts per million.

    If your ammonia levels test at moderate to low levels, you can go with the ammonia detoxifier removal method. This method is effective but does not work as quickly to eliminate ammonia. One or two doses will treat ammonia poisoning in your betta fish tank.

    If your levels are on the high side, go with the water change removal method. You will bring ammonia levels down faster this way. Saving the life of your betta fish!

    Ammonia Detoxifier Removal Method

    Step 1: Having tested your aquarium water for ammonia levels, add 5mL/10 gallons of ammonia remover to the tank.

    Step 2: Wait 2 days, then re-test your water using the test kit. If levels are still high, add another 5ML/10 gallons of tank volume and repeat as needed until ammonia levels lower.

    Water Change Removal Method

    Step 1: After you perform an ammonia test, perform up to a 50% water change using chemically treated tap water. This reduces your ammonia level in the tank by 50%.

    Step 2: Wait 12-24 hours and then perform a second water change of up to 50%. Waiting several hours gives your fish a chance to acclimatize to the sudden shift in water conditions.

    Even though the new tap water is clean, you are still causing a drastic change to pH and other parameters. This can cause stress enough to shock your betta fish if done all at once.

    Fresh tap water should also be warmed to the same temperature as your main tank. Adding a lot of water that is more than 4°F too warm or cold will also cause shock.

    How Long Does It Take For A Betta To Recover From Ammonia Poisoning?

    The faster you treat ammonia poisoning in your betta fish, the faster you will see it recover. The precise rate of time depends on the severity and duration of ammonia poisoning.

    If your betta’s tank has remained high in ammonia for a long time, the betta fish may need up to a week to recover. In the meantime, it will remain sluggish, eat little, and may show other symptoms of ammonia poisoning listed above.

    But if ammonia levels rise for just a short time, a betta fish can recover in as little as a day! Much faster than many of their tank mates. These are some of the hardiest fish in the aquarium world!

    How To Prevent Betta Ammonia Poisoning

    The best medicine is always prevention. Especially where ammonia poisoning is concerned. Here are a few strategies to keep toxicity at bay for good!

    Ensure You Have An Established Tank

    Your first line of defense are your nitrifying bacteria. Without them, you have no nitrogen cycle. And without a nitrogen cycle, nothing will remove ammonia from the fish tank.

    A new aquarium should always be stocked very lightly at first. As your first fish release small amounts of ammonia, bacteria start feeding on it. You then add a few more fish to the tank. Creating food for more bacteria. This is called cycling an aquarium!

    A “mature” or “established tank” is one that has undergone this process. And it has a colony of beneficial bacteria ready to munch on any ammonia that is released.

    Sometimes bacteria colonies die due to dangerous and sudden shifts in water conditions. Broad spectrum fish medications can also cause them severe stress. Normally, they recover fast from stress. But if you see a sudden rise in your ammonia level, try adding a booster of nitrifying bacteria.

    In the past, you had to rely on nature to gradually seed a new tank with these micro-organisms. Today you can buy nitrifying bacteria by the billions, instantly boosting the ability of your tank to process fish waste in the form of ammonia!

    Perform Regular Water Changes

    Regular water changes are crucial to the success of any aquarium. The exchange of old tank water for fresh new water can cause your fish to immediately perk up.

    Water changes remove ammonia that has built up and is not being processed by your bacteria. Which is critical if you have a brand new tank that is still cycling. Nitrite and nitrate are also removed through water changes.

    Nitrate, in particular, accumulates since nitrifying bacteria don’t feed on it. You need de-nitrifying anaerobic bacteria for that.

    Most aquariums have a few, but these organisms really only thrive in conditions where there is no oxygen. Such as under a deep substrate or micro pores in a filtration system with bioactive media.

    Quickly Remove Any Uneaten Food

    Rotten food is another common cause of ammonia poisoning in betta fish. If you feed too much all at once or too often, food will fall into the cracks between gravel bits. Left uneaten, it will decay into ammonia and other toxic compounds.

    If you accidentally feed too much, a small water change to catch the excess food is a good idea. Using your siphon hose, you can remove a little water. Replacing it immediately with treated, warmed tap water!

    Another strategy for dealing with uneaten food is to add a few tank mates as scavengers! The popular myth is that betta fish are too aggressive to keep with any other fish and must live alone. But the truth is that it’s just the males that are territorial. And even then, they are only vicious towards other male bettas.

    Betta fish can live with many other kinds of fish. Many algae eaters are also excellent scavengers and will sniff out pellets and flakes that are hidden in the substrate. But snails do the best job at collecting uneaten food before it causes ammonia poisoning.

    Smaller snails like ramshorn and bladder snails are good at getting into hidden places. They do reproduce very quickly, however.

    Add Live Plants

    Aquarium plants do a lot to keep your tank water pristine. They use all nitrogenous waste products as fertilizer. And ammonia is the most nutritious for them.

    You still don’t want detectable levels of ammonia, even in a planted tank, if there are fish present. It’s simply too toxic to animal health. But trace amounts are wonderful for lush plant growth. Small amounts of nitrate, on the other hand, are good for plants and won’t harm fish.

    Plants also release oxygen after they consume the carbon dioxide that fish exhale. They provide cover. And they compete with algae for light and nutrients. Keeping your tank as free of the green stuff as possible.

    Try adding plants known to grow fast. The excess growth can be trimmed and removed from the tank on a weekly basis. By trimming you also remove phosphates and other algae nutrients from the system!

    Here are some fast growing plants for beginners:

    • Hornwort (Ceratophyllum)
    • Elodea (Elodea densa)
    • Duckweed (Lemna minor)
    • Red Root Floater (Phyllanthus fluitans)
    • Banana Lily (Nymphoides aquatica)
    • Amazon Sword Plant (Echinodorus)

    Also make sure that you remove any dead plants or leaves when you find them. Dead plant material does release small amounts of ammonia as it decays.

    Not nearly enough to cause a spike like a dead fish would. But it is still waste that needs to be removed before it decays.

    Can Ammonia Poisoning Spread To Other Fish?

    Ammonia is a toxic chemical that is found in all of your tank water. So every animal in your aquarium is going to be affected if ammonia levels are too high.

    Betta fish are also more resistant to ammonia poisoning than most other fish. Once you see signs of betta ammonia poisoning, you likely already have dead fish of other species.

    Invertebrates are even more sensitive to high ammonia levels than aquarium fish. Snails, shrimp, clams, and other animals can die even if your fish look fine. And once they die, they decay quickly. Releasing even more ammonia into your fish tank.

    Can Ammonia Poisoning Kill A Betta Fish?

    Bettas are very hardy but they will die from ammonia poisoning if it goes on for too long. Once they show signs of stress, it is not too late. But you need to act fast to prevent death by ammonia poisoning.

    Fortunately, you have several ways of reducing ammonia levels in your tank water quickly. Once you do so, betta fish usually recover fast from ammonia poisoning symptoms.

    Your betta should stop acting listless, eat better, and show better colors in 24-48 hours of getting your ammonia level under control. It may take a few more days for any gill bleeding or discolored patches to go away.


    Ammonia poisoning in bettas is a dangerous issue to deal with. These fish are resistant to its effects. But they will still die if the ammonia level is not eventually corrected.

    I’ve outlined several strategies here for not only identifying the issue. But also treating ammonia poisoning in betta fish. Armed with this knowledge, you are sure to succeed in returning your tank’s water to good health!

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