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12 Reasons Your Glofish Are Dying In A New Tank!

The popularity of keeping glofish has gone from strength to strength over the last couple of years and although glofish are illegal in most parts of Europe due to being a genetically modified animal, they are extremely popular in North America.

Due to their popularity, we constantly see people asking a wide range of different questions about keeping glofish in a tank.

We already have an article going over glofish tank mates due to so many people asking about it but for today’s article, we want to be taking a look at why your glofish are dying in a new tank as many people reach out who are having this problem.

Thankfully, most of the more common reasons that your glofish may die in a new tank are very easy to fix provided you have a little time to correctly prepare so this article should be able to help a large number of our readers.

Why Your Glofish Are Dying In A New Tank!

We have our list of the more common causes of glofish dying in a new tank below:-

  • The Ammonia Cycle!
  • Poor Water Parameters!
  • Your Tank Size!
  • Stress And Anxiety!
  • Infection In The Fish!
  • Aggressive Tank Mates!
  • Poor Food Choices!
  • A Lack Of Oxygen!
  • A Rapid Change Of Water Parameters!
  • A Lack Of Cleaning!
  • Disease In The Fish!
  • Natural Causes!

With glofish being very popular choices with people new to the fish keeping hobby who have minimal experience with keeping fish in their tanks, we constantly see people having two, three or even four of these issues in their tank at the same time.

Due to this, we would recommend that you are least skim all of the article below to try and workout all of the potential problems in your tank causing problems with your glofish.

The Ammonia Cycle!

One of the main reasons that we see people struggling with glofish dying in their tank is down to the ammonia cycle not being completed in the tank.

The ammonia cycle is vital for any fish keeper to understand, regardless of what species of fish they have in their tanks as it directly impacts on the health and wellbeing of your fish.

In short, the ammonia cycle is the process where ammonia (which is very toxic to fish) is broken down into less harmful nitrites and then eventually into nitrates.

In an established tank, this process happens naturally as you have bacteria living in your filter media and substrate that break down the ammonia into nitrites and then nitrates.

In a new tank, this process does not happen naturally as you do not have these bacteria colonies fully established yet.

This means that if there is any ammonia present in your tank (whether it be from your fish waste or overfeeding) it will quickly build up to toxic levels which will kill your fish.

The only way to complete the ammonia cycle in a new tank is to do what is known as “cycling” the tank which is where you add ammonia to the tank on purpose and then allow the bacteria to colonise and break it down.

There are a few different ways that you can cycle a fish tank but the most common way is to use what is known as the “fishless cycle” method.

This is where you add pure ammonia to the tank on a regular basis and then test the levels of ammonia, nitrites and nitrates using a water testing kit until they are all at safe levels for your fish.

Once this has been completed, you can then add your glofish to the tank safe in the knowledge that they will not be exposed to any harmful levels of ammonia or nitrites.

If you do not cycle your new tank before adding your glofish (or any other fish for that matter), there is a very high chance that they will die due to the ammonia poisoning.

Poor Water Parameters!

Another very common reason that we see people struggling with glofish dying in their tank is due to poor water quality.

This can be for a number of different reasons but the most common one is simply not doing enough water changes.

As we mentioned above, the ammonia cycle is vital for any fish keeper to understand as it directly impacts on the health and wellbeing of your fish.

Issues with pH levels, hardness and chlorine levels can also have a direct impact on the health of your fish so it is important to test for these on a regular basis using a water testing kit.

If you are not sure what the ideal levels should be for your glofish, we would recommend that you speak to your local fish store or look online for guidance as there are diffierent species of glofish that need different water parameters.

Your Tank Size!

Another common issue that we see with people keeping glofish is that they are not keeping them in a tank that is big enough.

Whilst glofish are relatively small fish, they still need a decent amount of space to swim around and be happy and healthy.

There is plenty of guidence on tank size for your specific species of glofish on the glofish website but if you are new to the fish keeping hobby, we would actually recommend that you go with a larger size tank or intentionally keep your tank understocked.

So many beginners overstock their glofish tank causing issues with the fish dying quickly and this really is easy to avoid.

Stress And Anxiety!

Another common issue that we see with glofish (and other fish for that matter) is stress and anxiety.

There are a number of different things that can cause stress and anxiety in fish but the most common ones are sudden changes in the water parameters or tank mates.

If you have recently added any new fish to your tank or changed anything about the setup of your tank, this can be a major cause of stress for your fish which can lead to health issues and eventually death.

It is therefore important to make any changes slowly and gradually so that your fish have time to adjust and get used to their new surroundings.

Not Enough Oxygen!

Another common issue that we see with people keeping glofish is that they are not getting enough oxygen in their tank.

There are a number of different ways that you can increase the oxygen levels in your tank but the most common way is to use an air pump and airstone.

Another way that you can increase the oxygen levels in your tank is to add live plants as they will help to produce oxygen through photosynthesis.

Infection In The Fish!

Another very common reason that we see for glofish dying is infection.

There are a number of different infections that fish can get but the most common one is columnaris.

This is a bacterial infection that can be caused by a number of different things but the most common one is poor water quality.

If you notice any of your fish displaying symptoms of columnaris such as white patches on the skin or fins, you should immediately isolate that fish and treat the infection.

If you do not treat the infection, it will quickly spread to the other fish in the tank and can kill them all within a matter of days.

Parasitic, viral, and fungal infections as well as other types of bacterial infection can also be accidently added to a tank by beginners too so these are all things that you should keep an eye out for.

Aggressive Tank Mates!

Another common issue that we see with glofish is that they are being kept with aggressive tank mates.

Whilst glofish are relatively peaceful fish, there are some species of fish that will bully and harass them which can lead to stress and eventually death.

If you are not sure whether the fish that you are thinking of keeping with your glofish are compatible, we would recommend that you do some research or speak to your local fish store for advice.

Please keep in mind that the different species of glofish are not all able to be kept in the same tank without issues with aggression either.

Poor Food Choices!

Another common issue that we see with glofish is that they are not being fed the correct diet.

Whilst glofish are not particularly fussy eaters, there are still some things that you should and should not feed them.

One of the most common mistakes that we see people making is feeding their glofish live food that has not been properly quarantined.

This can lead to your glofish becoming infected with a number of different diseases which can eventually kill them.

It is therefore important to make sure that any live food that you are feeding your fish is from a reliable source and has been properly quarantined before being added to the tank.

A Rapid Change Of Water Parameters!

Another common issue that we see people having with their glofish dying is due to a sudden change in water parameters.

This can be for a number of different reasons but the most common one is simply doing a large water change and not allowing the new water to properly adjust to the temperature and chemistry of the tank before adding it.

This can cause a sudden change in water parameters that can be too much for your fish to handle and can lead to them becoming stressed and eventually dying.

To avoid this, you should always slowly add the new water to the tank over a period of an hour or so and make sure that it is the same temperature and chemistry as the water already in the tank.

A Lack Of Cleaning!

One of the most common reasons that we see for people’s tanks becoming polluted and their fish dying is simply due to a lack of cleaning.

As you probably already know, fish produce a lot of waste and if this waste is not removed from the tank, it will quickly start to break down and release toxins into the water.

These toxins can quickly build up to lethal levels and kill your fish.

It is therefore important to make sure that you are regularly cleaning your tank and removing any waste that has accumulated.

A good rule of thumb is to do a partial water change of around 25% every week and a full clean of the tank every month.

Disease In The Fish!

As we mentioned earlier, one of the most common reasons that glofish die is due to disease.

There are a number of different diseases that can affect glofish and some of them can be deadly.

The best way to avoid your fish getting sick is to make sure that they are healthy before you add them to your tank.

You can do this by buying them from a reputable source and quarantining them for at least two weeks before adding them to your main tank.

Natural Causes!

Finally, it is worth mentioning that sometimes fish just die for no apparent reason.

This is often referred to as “old age” and is simply a natural part of life.

There is not much that you can do to prevent this from happening and it is something that you should be prepared for if you are planning on keeping fish for a long period of time.

If you are concerned about your fish dying from old age, we would recommend that you speak to your local fish store for advice on how to prolong their life.