Common Problems In Fish

When it comes to your fish, you want to make sure they are in tip-top condition. After all in most aquarium setups, the fish are centre of attention. You want them to be healthy, vibrant, and to be happy in their surroundings. But, because they are living things you will almost certainly get health problems with them at some stage. Health problems can be caused by several different factors such as water parameters, stress, and overfeeding. let’s look at some common problems in fish and how to cure them.

Why Is My Fish Bleeding?

The most common cause for why your fish is bleeding is ammonia poisoning. One of the first signs will be your fish gasping for air at the water’s surface. This quite often is one of the first signs that your water conditions need looking at. If left untreated it will lead to the gills becoming extremely sore, turning a dark red, and eventually bleeding. Ammonia poisoning can and will be fatal if it’s not sorted out straight away. As you can imagine this problem is caused by a build-up of ammonia in your aquarium.

The build-up will be caused by things such as overfeeding, fish waste, and decomposing plant matter. Untreated tap water can also be a major factor. To keep ammonia levels down keep your aquarium nice and clean. Do regular water parameter checks and a 25% water change once a week. When feeding the fish be sure to check no food gets leftover, if this is the case then cut down on your feeding.

Why Does My Fish Have White Spots?

White spots are a very common problem in fish and are caused by very small parasites. This condition goes by the name of white spot disease, otherwise known as ich. Ich is very common in fish but can be a bit of a pain to get rid of. This is mainly down to the fast reproduction rate of the parasite. In the early stages of Ich, the fish’s behavior will change, fins could be folded down and their swimming can be erratic or disorientated.

Eventually, you will see the infected fish will probably start scratching themselves up against objects. This means the parasites are getting into their skin. They will also infect the gills which will cause further stress and breathing difficulties for the fish. Eventually if left untreated all the fish in the aquarium will get Ich and die.

How Does Ich Get In My Tank?

The parasites that cause Ich can get into your tank in several different ways. Adding fish to your tank that is already infected with the parasite is probably one of the most common ways. Always give fish a good once over before adding to your setup. The cunning little parasites can also hitch a free ride on living plants. Be sure to give them a good clean before introducing them to your tank.

How Do I Get Rid Of Ich?

It is highly advisable to always have a quarantine tank as well as your main setup. This ensures you have somewhere to treat your poorly fish. To sort out the Ich in your tank I would first put all your fish in the quarantine tank, be sure to check the water quality first. Then, in your main tank bump the temperature up to 96F and leave for 2 days. This should kill the parasites in your main tank.

Over at the quarantine tank bump up the temperature 2 degrees every 12 hours until you reach 86F (30C). Most tropical fish should be good with this temperature, but just do some research to be sure, there are always exceptions. After 2 weeks in these conditions, the fish should start recovering. There are also plenty of treatments out there for white spot disease. It is worth noting these will only work at the early stages of the disease when the parasites are still visible. Always have a good look at the instructions when adding any type of treatment to your tank.

Why Does My Fish Have Bulging Eyes?

Another one of the many common problems in fish is bulging eyes. If you notice that any of your fish start to get bulging eyes, it is probably a sign of ‘popeye’. Popeye is a condition that can be caused by things such as your fish knocking its eye on something, Your fish getting into a fight with another fish, or even poor water parameters. All of these scenarios can lead to an infection in the eye and cause a buildup of fluid. The fluid in turn pushes the eye forward in its socket. If left untreated it will lead to blindness in the infected eyes.

How To Treat Popeye

If any of your fish are showing signs of popeye it is a good idea to quarantine them straight away if possible. The next thing to do, like with most fish health problems, is to check your water parameters and get them how they should be. Obviously, this can vary slightly depending on what fish you have.

Once you have your parameters sorted it is time to concentrate on the infected fish.

Over in the quarantine tank get yourself some antibiotics suitable for curing popeye. These are like a general antibiotic, like the type that is meant for fin rot, etc. Follow the instructions on the product closely and add to the water accordingly. Hopefully, in time, you will see the eyes start to go back to normal.

Why Is My Fish Swimming Upside Down?

If any of your fish are swimming upside down, the chances are it will be experiencing problems with its swim bladder. The swim bladder is a small pocket of air inside a fish that helps with its buoyancy. If the fish is having swim bladder problems it could lead to the affected fish swimming upside down, on its side, or just not swimming at all. This condition is called swim bladder disorder. This term kind of covers several different problems that could be affecting the swim bladder. Listed below are the main ones.

Low Water Temperature

Believe it or not, the low water temperature can lead to problems with the swim bladder. If your water temperature is colder than it should be, then it can mess with the digestive system. Inturn causing a build up inside the fish and puts pressure on the swim bladder. Be sure to check your parameters are setup right for the fish that you keep.

Infections And Parasites

Bacterial infections and parasites can also be the cause of swim bladder disorder. Parasites can easily be introduced to aquariums unknowingly on fish and plants. Be sure to examine fish thoroughly and clean all plants before adding them to your tank.


Constipation can lead to problems with the swim bladder. To combat this, try adding a higher dose of fibre in the diet.

Why Has My Fish Got A Flat Dorsal Fin?

If the dorsal fin on one of your fish is flat against the body and not upright like it should be there is something wrong. The dorsal fin is the fin on top of the fish’s back. If it is folded against the body, the chances are it will have ‘clamped fins’. Clamped fins are a sign of stress in your fish and are usually caused by one of two things. Poor water quality is probably the most popular, closely followed by parasites.

The first thing I would do is a 25% water change and check the water parameters. Keep a close eye on the infected fish for the next couple of days. If you have a quarantine tank it wouldn’t do any harm to plop the fish in there for a day or two. If you have reason to believe the clamped fins could be a result of infection or parasites, you will need to treat them with the appropriate treatment. A general antibiotic such as Tetra Lifeguard should do the trick. Just be sure to follow the instructions exactly as they say on the product.

To Conclude Common Problems In Fish

A lot of the common problems in fish are avoidable in the first place. Water parameters is probably one of the biggest factors in fish health. If you keep your water levels as they should be this will dramatically increase your chance of keeping healthy fish. Bad water conditions will lead to stressed fish. Stressed fish are prone to attacks from bad bacteria and disease. It is also worth monitoring any additions to your tanks such as plants and new fish. It is always worth quarantining any newcomers, in case they are carriers of unwanted pests such as parasites.

Frequently Asked Questions

Is Cottonmouth in fish Contagious?

Yes, Cottonmouth is a disease that is highly contagious and one of the common problems in fish. The bacteria is a bit of a bully and only picks on sick or stressed fish. It is a bacterial disease that can be treated with antibiotics.

Is my fish constipated?

Constipation in fish can become fatal if not treated. If your fish is constipated it could have a swollen abdomen or be showing signs of a swim bladder disorder. To cure constipation, up the fibre content in your fish food. Like with humans, fibre will certainly help your fish poo.

What are gill mites?

Gill mites are small parasites that feed off your fish’s blood. They do this by attaching themselves to the skin and gills. A sign of gill mites is when your fish spend time at the surface of the water gasping for air. This is because the parasites have latched onto the gills and are causing the fish problems with breathing. On closer inspection, you will probably notice that the gills don’t open and close as they should. To successfully kill off these parasites you will need to use Octozin and Sterazin. Check all instructions carefully before applying any treatment.

How can I tell if my fish has internal problems?

Internal problems in fish are usually caused by parasites feeding on your fish internally. One sure sign of this is zero weight gain. If your fish is eating well but not gaining any weight or losing weight, it is probably an internal problem. Another thing to look out for is the colour of the fish’s poo. If it is a white colour rather than a reddish-brown it has probably got internal issues.