18 Common Diseases Your Fish May Have (And How to Cure Them)

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There are always health risks when owning fish, but this guide to common fish diseases will allow you to identify, diagnose, and provide you with suggestions on what medications to administer to the affected fish. You’ll be able to know what symptoms to look out for and how to prevent them.

I have a great video to share from our YouTube channel with you to start off. I will also go over treatment plans for every aliment below.

1. Anchor Worms

Anchor Worms

Anchor worms are not actually a type of worm but a large parasitic crustacean from the Lernaea species that can live on your pet fish. Pond fish are most commonly infected with this species. They will attach to their skin and bury their head into their muscles.

Symptoms of Anchor Worms

A common sign with Anchor worms would be red and inflamed scales. If you look close enough, you may even be able to see the body of these parasites sticking out! Their bodies will look like whitish green thread stuck to your fish. You may also notice that your fish is rubbing its body up against things in its tank. Other symptoms may include lethargy, ragged fins, and mucous production.

Treatment of Anchor Worms

For larger species, anchor worms can usually be easily removed by carefully pulling on the body of the parasite. After you have removed the parasites, you can apply topical antibiotic ointment to their scales.

Treatment includes using anti-parasitic medications and performing water changes. It would be best if you also cleaned the whole tank to get rid of any of the eggs, larvae, or parasites in the tank.

For smaller species, using Hiraki USA Cyropro works without affecting your biological filtration.

2. Bacterial Infections

Your fish can get a bacterial infection. These commonly happen after an injury. A common bacteria you will encounter is Aeromonas salmonicida1.

Aeromonas salmonicida

Causes of bacterial infections

Many times the cause of these bacterial infections is due to poor water quality and poor diet. This can cause stress in your fish leading to a lower immune system and allow any bacterial infection to set in.

Signs of a bacterial infection

For a bacterial infection, these are some of the most common signs that you will see:

  • Red spot on the fish’s body
  • Ulcers on gills
  • Enlarged eyes
  • Swollen abdomen

Other signs are rapid gill movement, discoloration, and skin ulcers.

Treatment of bacterial infections

If a bacterial infection occurs, your vet will prescribe antibiotics based on the bacteria that is present. There are some medications that you can buy online or at a local aquarium store to help treat bacterial infections.

Administer antibiotics to handle the infection. A popular brand for many hobbyist to recommend is API’s Furan-2 or Triple Sulfa. These are medications that you put into their water. Livestock will need to be transferred to a quarantine tank or hospitalized tank while they are being treated. Before going back to their main tank, the issue with the tank would need to be corrected, and the tank cleaned.

Also consider adjusting the tank population to control the spread and preventing in the future. Many bacterial infections are usually caused by unclean water and other factors.

3. Constipation

If your fish can not poop, they will quickly become constipated. This can cause them to become very ill.

Causes of Constipation

There are two main causes of constipation:

  1. Improper diet
  2. Parasite infections

Both of these can cause your fish to not be able to properly pass feces

Symptoms of Constipation

If your fish is constipated you may notice a bloated abdomen. Constipation can cause them to develop swim bladder disease so you will see signs of buoyancy issues, such as difficulty swimming. Other indicators include loss of appetite and bloating.

Treatment of Constipation

One of the easiest ways to treat a constipation is enhance nutrition by increasing the amount of fiber in their diet and use deworming medications. Another way to treat constipation is to dose your fish tank with Epson salt (API sells a product that is easy to find in stores). Adding 1 to 3 teaspoons of salt per every 5 gallons of water will help. Epson salt will act as a muscle relaxant and help them be able to poop easier.

4. CO2 Poisoning

CO2 levels over 30 ppm can be dangerous for aquatic animals. This issue can arise with fish tanks that use CO2 injection in planted tanks.

Signs of CO2 Poisoning

If your aquarium has high levels of CO2 you will notice rapid breathing and gasping for air. You also may notice that these fish are spending more time near the surface of the tank. Also look for abnormal swimming, breathing difficulty, and lethargy.

Causes of CO2 Poisoning

CO2 poisoning in can be caused by your CO2 reactor not working, or your plants not absorb CO2 due to the lights not working properly.

Treatment for CO2 Poisoning

The best way for you to treat CO2 poisoning is to use an air stone to agitate the surface. This causes the carbon dioxide to dissipate from the water. You can also adjust the rate of CO2 injection in your tank.

5. Flukes

Gill Fluke

Flukes are external parasites (Source- Cuttlebrook Koi Farm). Most flukes will affect fish gills. The two most common flukes that are seen are Dactylogyrus and Gyrodactylus. There can be body flukes or gill flukes. Let’s discuss the causes.

Causes of Flukes

These flukes can commonly enter your aquarium from another fish that is infected with flukes.

Symptoms of Flukes

Flukes will attach themselves to your fish’s gills and skin. This can damage these areas leading to a secondary bacterial infection. Other symptoms include slime coat changes and gill damage.

Treatment of Flukes

The most effective treatment for flukes is Praziquantel. Apply antifungal treatments and conduct veterinary consultations or expert hobbyists for proper management. After you have treated these flukes, you can treat any wounds that these flukes they left with antibiotics.

6. Clamped Fins

Clamped Fins is just like it sounds, it occurs when your fish’s fins are clamped close to their body.

Causes of Clamped fins

Most fish will hold their fins very close to their body if the water condition is not correct. It could also be caused by external parasites.

Symptoms of Clamped Fin

For clamped fin, you may notice lethargic behavior and holding their fins very close to their body even while swimming. They may exhibit clamped fins along with white patches and spinal deformities.

Treatment of Clamped Fins

If you see symptoms of clamped fins, it is best for you to check your water conditions. Also, look for any external parasites. If you see any parasites, you will need to manually remove the parasites. Isolate new additions and implement UV sterilization to prevent spread in the future.

7. Dropsy

Dropsy is a term used to describe a fish that is swelling due to kidney disease.

Symptoms of Dropsy

Usually, the signs of dropsy that are seen are a slightly swollen belly all the way to a very swollen abdomen so much that their scales will stick straight out, causing them to look like a pinecone. Other notable symptoms include scale loss and exophthalmia (bulging eyes).

Cause of Dropsy

There are many things that can cause your fish to have kidney issues. These are some common reasons:

  • Stress
  • Polycystic Kidney Disease

Treatment for Dropsy

The first thing to do about Dropsy is to put the affected animal in a quarantine tank. This can help eliminate the stress that may be in the display tank if they improve while in the quarantine tank, there is a stressor in the main tank that needs to be addressed. This may be poor water quality, parasites, overcrowding, or something else. Try to figure out what is causing the stress, and fix this issue.

Dropsy is a serious disease that can lead to the loss of your prized pet’s life. It is best for you to see a vet. Some vets will see fish; however, it may be hard to find one near you. Reaching out to your local aquarium store, you may be able to get suggestions on who to see to help treat your fish.

I know both of these are not always available to some, so I’m going to defer to Lori’s Hartland’s experience on how she cured her Goldfish using a triple treatment of Kanaplex, Metroplex & Epsom Salt. Here is the full video below that walks you through her experience. It’s also very important to see her experience with her vet call at 19:06. She had to take a phone consultation, which is going to be what most will get when consulting a vet for a smaller species.

Other blog material you find may tell you to use salt baths, but in my experience, this doesn’t work too well. Lori’s treatment plan and using wheelchairs have been the most effective for me.

8. Freshwater Ich

Ichthyobodo is a protozoan parasitic infection seen in fish who are stressed.

Symptoms of Ich

Ich attacks your fish’s gills and skin. These parasites will cause your fish to have a grey color to their skin. You will notice that the affected animal will be lethargic, weak, and not want to eat. You may notice that they spend more time near the top of the tank, gulping air or rubbing their side on their tank. Also, watch for white feces, scratching against objects, and rapid gill movement.

Freshwater Ich

Cause of Ich

Stress is the main cause of Ich. This can be due to poor water conditions, overcrowding, or illness. When your fish is stressed, it leads to a lower immune system and allows this protozoal parasite to take over.

9. Freshwater Velvet (Gold Dust Infection)

Freshwater Velvet

Velvet disease in fish can be very deadly for your whole tank. This disease can quickly wipe out everything in your tank.

Symptoms of Velvet

Fish who have velvet will be scratching their body against any hard surface in the tank. This is to try to remove the parasites from their skin. They may also display some of the following signs:

  • Lethargic
  • Rapid Breathing
  • Not eating and weight loss
  • Holds fins next to body
  • Labored or rapid breathing
  • Yellow to rust color dust on the body
  • Pealing of the skin in severe cases
  • Cloudy eyes

Causes of Velvet

Velvet is caused by the parasite Oödinium pillularis or Oödinium limneticum. These parasites are common in tropical fish and may be present in many aquariums but only cause issues if your fish is stressed, sick, being transported, has a sudden, temperature change or has poor water quality.

Treatment of Velvet

If your fish has velvet, you do a few things to help with treatment.

  • Increase the temperature of the water by just a few degrees. Monitor water temperature to ensure it stays elevated.
  • Dim the aquarium lights for a few days
  • The treatment of choice for velvet is copper sulfate for 10 days. A good brand to look for is Copper Power or SeaChem Cupramine. DO NOT use copper sulfate in a displayer tank. A removal of the sick fish to a quarantine tank is a must!

Velvet can many times be prevented by quarantining any new additions that you are planning on adding to your tank, providing your aquatic livestock with a proper diet, and maintaining good water quality. If you came here to get info on the saltwater version, check out Mark’s article on Marine Velvet.

For future prevention, consider implementing biosecurity measures like quarantining new additions.

10. Fungus


The two common fungus infections seen in the freshwater side of the hobby are:

  • Saprolegnia2 and 
  • Ichthyophonus hoferi 

Symptoms of Fungal Infections

Fungal infections can cause damage to internal organs. Common signs seen in fish with fungal infections are grey cotton-like growths and coloration seen on the skin, gills, fins, and around the eyes.

Causes of Fungal Infections

Fungal infections are caused by unclean water conditions and dead and decaying organic material in your tank.

Treatment of Fungal Infections

The first thing you need to do to treat fungal infections is to clean their tank fully. Then using potassium permanganate that you put into your aquarium water. You will want to make sure that you have removed any external pathogens from your fish’s skin.

A popular brand of fungal treatment that you can use after fully cleaning your aquarium is API Fungus Cure. Apply this topical treatment and disinfect aquarium equipment to control the fungus.

You can also increase the water temperature to 82 degrees as most of these fungal infections thrive in colder temperatures.

11. Gill Mites

Gill Mites

Gill mites3 are common parasites that are seen in aquariums. These parasites attach to your fish’s skin and feed on their blood.

Symptoms of Gill Mites

If gill mites are present, you will notice that their gills do not fully close. These mites prevent the gills from being able to function properly. This will cause your fish to spend most of its time at the surface of the tank gasping for air. Also look for abnormal swimming and red streaks on the body.

Causes of Gill Mites

These mites enter your tank from new livestock additions who already have these mites. This is one reason why it is advised to always quarantine any new additions before adding them to your aquarium.

Treatment of Gill Mites

To treat gill mites, you will need to use medications such as sterazin and octozin. You will need to repeat this treatment about 5 days later to kill any other mites that may have hatched.

I read somewhere that another blog stated apply immunostimulants and adjust lighting conditions for recovery. I think that’s false. You can refer to this article regarding immunostimulants in fish – they aren’t well studied.

12. Hole In The Head

Hole In The Head Disease

Hole in the head disease (also known as Hexamita) is seen when there are small indentions in your fish’s head or along their lateral line.

Symptoms of Hole in the Head

A common symptom of hole in the head are small indentions into their skin. These will start as slight depressions and can advance to more severe holes. Some fish with this illness will stop eating. This disease often causes fecal changes and parasitic cysts.

Causes of Hole in the Head

Hole in the head is caused by a a protozoan called Hexamita. It is a common disease in Discus. Another factor is deficiency of minerals in water due to the use of RODI water or excessive usage of activated carbon.

Treatment of Hole in the Head

The best way to treat this is in a quarantine tank and treating with Metronidazole or API General Cure.

You can feed medicated food using focus and General Cure or Metro.

13. Hemorrhagic septicemia

Hemorrhagic septicemia

Hemorrhagic septicemia is a deadly viral infection seen in fish caused by Piscine novirhabdovirus.

Symptoms of Hemorrhagic septicemia

This disease will cause bleeding in their internal organs, muscles, and skin. This can be seen as small red dots on your fish’s skin. You can also see some of the following symptoms:

  • Pale gills,
  • Dark-colored body,
  • Fluid accumulation in the body,
  • Bulging eyes 

Other signs include hemorrhages and sudden death in livestock.

Treatment of Hemorrhagic septicemia

There is no really good treatment for this disease. Many fish who get this illness will die of this infection. You can try to clean the tank and increase the temperature of the water that the fish are in a few degrees. You can try to administer antibiotics such as:

  • API Triple Sulfa
  • Kanamycin
  • Thomas Labs Fish Mox

Do not use carbon filters when using medications. While they improve water quality, they will remove medication.

14. Lice

Your fish can get external parasites such as lice. Fish lice are small parasites that can attach to the skin and suck blood, causing the fish to become anemic.

Symptoms of Lice

If your fish has lice you may see a small clear disc laying next to their body. Most fish who have lice infestation are pale due to the lice sucking blood. They may also be rubbing against surfaces in the tank as they try to remove the lice themselves. This can cause them to have external wounds on their skin. Other symptoms may include isolation from the group and skin ulcers.

Treatment of Lice

The best way to treat lice is to physically remove all the lice from your fish’s skin. If there are any external wounds, you can treat these areas with topical antibiotic ointment. Over the counter medication of choice would be diflubenzuron under the brand name Dimilin-X. It’s an anti-parasitic medication highly effective at eliminating lice.

Consider implementing quarantine protocols going forward to prevent future infections.

15. Pop-Eye

Popeye Fish

Pop-eye is due to a bacteria infection that causes one or both eyes to pop out of the socket.


This condition is usually very easy to diagnose as you will see bulging eyes (also known as exophthalmia) protruding from their eye sockets. Behavioral changes that include loss of appetite are also common symptoms.


Pop-Eye is usually due to a bacterial infection. It can also be due to vitamin A deficiency, mass behind the eye, or poor water quality.


Pop-eye is commonly treated with tetracyclines. You can get this medication from your local veterinarian. Also, you will need to check the water quality in your tank and fully clean their tank. If you cannot get a medication from a vet, you can try over the counter sulfa drugs like SeaChem SulfaPlex.

16. Swim Bladder Infection

The swim bladder is an organ in your fish that contains oxygen and other gases so that they can be buoyant. If their swim bladder does not function properly, they will have trouble maintaining their desired depth.


One of the main signs that you will see with swim bladder disease is that your fish has a hard time staying upright in their tank. They may also spend a lot of time near the surface or deep in the tank. They will have abnormal swimming and a loss of appetite.


Poor water quality and stress are common causes of this condition. Newly purchased fish may get this disease if transported incorrectly (common with imports or species caught in the wild). If you notice that your fish cannot maintain proper buoyancy, the first thing you need to check is the water quality in your tank.


If your fish does have swim bladder disease, it would be best for you to see an aquatic vet. An aquatic vet is able to perform a procedure to release the air from the swim bladder to correct the issue (known as venting). They will also recommend that you test your tank’s water condition and perform water changes of about 10%.

Fish who have trouble staying upright or spend a lot of time near the tank’s bottom may need to learn how to be hand fed. This will help ensure that your fish is getting the proper nutrition that it needs to survive. Hobbyists have also tried making harnesses to keep their pet upright, like the video below. Check out Mark Kennedy’s video for the full walk-through. The harness solution is most effective with fancy goldfish.

17. Tail and Fin Rot

Causes of Tail and Fin Rot

Fin rot is usually caused by unclean and improper water quality and an injury to one of these areas. This cut or abrasion can then easily get infected due to unclean water. This can cause these areas to rot.

Signs of Tail and Fin Rot

You will see fraying and torn fins (or fin erosion), ragged fins, tails, and nodules on the skin.

Treatment of Tail and Fin Rot

There are medications that you can get to treat these infections, such as SeaChem KanaPlex and API Fin and Body Cure. You can also use Methylene Blue from Kordon to treat your tank. It is best to put 1 drop per every 2 gallons of water. When using Methylene Blue, you will need to do a 50% water change every other day for a week.

18. Mouth Rot

Mouth rot is caused by a fungus called Flavobacterium bacteria.

Signs of Mouth Rot

Look for discoloration and white patches on the mouth area. If your fish has mouth rot, you will see a white cotton-like appearance around their mouth. If this is left untreated, the skin around their mouth will start to rot.

Causes of Mouth Rot

This is usually caused by unkept water conditions and stress. This lowers their immune system causing fungus to take over.

Treatment of Mouth Rot

There are many antifungals that you can buy at your local aquarium store to help treat this issue such as:

You should also try to figure out what is causing your fish to be stressed and check the water condition.

Other Common Illnesses

In addition to the diseases already covered, there are several other common ailments and parasites that can affect fish in aquariums and ponds. I didn’t have the space in this post to cover them all but here is the list so you can be aware of them. Over time, I will do blog posts about these.

  1. White Spot Disease – A highly contagious parasitic disease common in ornamental fish.
  2. Neon Tetra Disease – Affects neon tetras, causing wasting and color loss.
  3. Fish Tuberculosis – A bacterial disease that can be serious.
  4. Columnaris DiseaseColumnaris is a bacterial infection known for affecting gills, mouth, and skin.
  5. Nitrite Poisoning – Occurs due to high levels of nitrite in water.
  6. Ammonia Poisoning – Caused by elevated ammonia levels in the aquarium.
  7. Black Spot Disease – Parasitic infection causing black spots on skin.
  8. Lymphocystis – A viral disease causing growths on fins and body.
  9. Red Pest Disease – Bacterial infection causing red streaks on the body.
  10. Vibriosis – A bacterial infection affecting internal organs.
  11. Whirling Disease – Causes erratic swimming and skeletal deformation.
  12. Camallanus Worms – Intestinal parasites visible near the fish’s anus.
  13. Oodinium – Also known as “Rust” or “Marine Velvet” disease.
  14. Carp Pox – Causes waxy, skin growths primarily in koi and carp.
  15. Cotton Wool Disease – A fungal infection that looks like cotton wool.
  16. Koi Sleeping Disease – Affects koi and carp, causing lethargy.
  17. Scale Protrusion – Scales protrude due to fluid buildup.
  18. Nematode Infections – Roundworm infections.
  19. Epistylis – A parasitic infection causing cotton-like tufts on the body.
  20. Brooklynella – A protozoan parasite affecting the skin and gills. Clownfish are susceptible
  21. Chilodonella – A parasitic infection affecting skin and gills.
  22. Uronema Marinum – A marine parasite causing severe damage.
  23. Argulus (Fish Louse) – A large, visible parasite that attaches to the host’s body.
  24. Skin Ulcers – Often bacterial in nature, causing open wounds on the body.

Prevention Steps

There are many things that you can do at home to help prevent many of these issues. Your aquatic pet’s health depends on the water condition, diet, and levels of stress. To help keep your fish healthy, try doing these best practices below:

  1. Provide a Quality Diet: Your fish should be fed a proper diet every day. Diet will help keep your fish full and not fight with other tankmates in the tank over food.
  2. High Water Quality: Make sure that the water that your fish is living in is clean using highquality power filters or canister filters and at the correct temperature. Also, check to make sure that the levels in your aquarium or outdoor pond are correct.
  3. Observation of tank: It is best to observe all livestock in your aquarium daily. This will let you know if any inhabitants are sick or stressed. Early detection of a disease is easier to treat than one that is not detected until later in the disease stage.
  4. Reducing Stress: Make sure that you reduce the stress in your tank. If you have a fish that is bullying other tankmates or you have just added a new fish to the tank, make sure they are not overly stressed.
  5. Quarantine New Additions: Any addition to your tank should be quarantined for a few weeks to make sure that you are not putting an infected fish (or plant – yes plants can be infected too!) into your tank. This gives you a few weeks to make sure that your fish is eating and not showing any signs of illness before putting them in your main tank. Mark has a great article on quarantining. It is marine fish based, but the same principle applies for freshwater fish.

Creating A Medicine Cabinet

Anyone who has multiple aquariums deals with sick fish. Whether you quarantine or not, it’s a based practice to have medication on hold for emergencies. Here would be common readily available medications that are helpful to have on hand. To summarize all the medications discussed, I have added a table for quick reference.

Parasitic (External)Ich-X, Prazipro
Parasitic (Internal)General Cure, Seachem Metroplex, SeaChem Focus (To Bind)
FungalAPI Fungal Cure
BacterialAPI-Furan 2, Seachem Sulfaplex


What are the most common issues?

The most common fish diseases are Ich, internal parasites. Read more about fancy goldfish. Hole in the Head disease is common with Discus.

How Do You Identify Different types of Infections?

The most obvious way to identify a disease are external signs. You may notice odd behavior in the fish (such as flashing, scratching), cloudy eyes, or a whitish coatings on its body. Another obvious sign is a skinny fish that is eating, a common sign of an internal parasite. Identifying a disease is critical to treating them in time.

Can You Get Heath Issues From Them?

No. You cannot get a disease from an aquarium fish unless you eat them. Since we do not eat our aquarium inhabitants, getting ill from keeping aquariums is very rare. As long as you care for your livestock and clean your hands after putting your hands in your tank, you should not have any concerns with getting sick due to keeping an aquarium.

How Do you Deal With Health Problems?

Dealing with disease involves treatment. You must first know what type of disease you are dealing with – parasitic, bacterial, fungal, or internal. Each type has different ways of treating it. There are many store-brand medications these days. For large fish, Vets can prescribe medication. This is more common for large fish like Koi and Cichlid. Small species will often get a consultion from a Vet, but don’t expect them do any procedures.

How Do I Know If they have Internal Parasites?

The most obvious way to know if your fish has an internal parasite is weight loss. If your fish is eating and says skinny it likely has an internal parasite. The other is the shape and color of the poop. If you see stringy white poop, this is a sign of an internal parasite. Most internal parasites can be treated with Metroplex

Want to learn more about how to keep a tank clean? Check out this guide on how to clean an aquarium to learn more.


  1. My goldfish were healthy one day the next day lethargic one died. His eyes are completely black some of the other have black eyes. Also, I fear they will all die. I searched the Internet, but cannot find anything on this please, can you help me

    • Hi Mike sorry to hear about your losses. The losses sound sudden. How long have you had the tank, how many fish were in it, and did you test your water recently?

      Did the fish show any signs of distress before passing away?

  2. I have discus , one of them started darting around the tank . When he has this episode he goes into a dead stop. He looks like he is dead and then starts moving. What is causing this and how can I cure it

      • I got a new large external filter for my fish tank 6 days ago and changed 50% of the water. my two goldfish that I’ve had for 5 years were perfectly fine until yesterday they became a bit inactive and then today I noticed one had a white coating on him. later today his tail turned red and he has red spots on his belly. I don’t know if this is related to ammonia (water change) or stress from the new filter?

      • Hi Sarah,

        When you replaced your filter did you replace all your media? If you replaced your own filter with a brand new filter, you likely have high ammonia levels.

  3. Hi!
    My blue Betta Halfmoon has had a light grey spot that is slowly spreading to his skin.
    What is happening, and what is the treatment?

  4. Hi Mark
    Ive treated my tank with Blue Planet Fungal Cure according to the instructions and still have a white spot appearing on my Tiger Oscars right pectoral fin.
    Ive been through the process twice before, thinking Id fixed it, and this time I did the three day treatment twice in a row, apparently with good results. I then followed it up immediately with another of the same treatment just to be sure, and overnight the white spot returned !
    I have noticed that hes very recently gone back to shovelling gravel around with his mouth, something he seemed to have stopped doing as much.

    We feed him with floating fish pellets, keeping them to a minimum rather than letting him have food constantly available.

    Hes around 18 months old and shares a 130 or so litre tank with two mature silver dollars which get fed two pinches of algae flakes twice daily.

    The water quality is usually fairly good according to the testing ive had done and kept at around 27 degrees celcius.

    Any ideas ?Feel free to email me if you can.

    Many thanks 🙂

  5. I am having big size gold fish, last 1 day it is well & very fast breath , swim in tank and down in the bottom and suddenly it swim very fast and jump from tank.. I have change the water also no changes.. let me know the solution

  6. I have two goldfish in a tub in my garage. They are 8-10 inches and came out of a 250 gallon pond that I just rebuilt last year. There were three of them, but one has died. They hung at the top of the water with theiur backs exposed. I assune the skin dried out and possibly got sunburned. Then they developed a fungus. Had them tested for parasites and the orange one jumped out of the guys hands and hit the floor pretty hard. Ive been treating them with a fungal solution and doing a 25% water change to try to keeo the water clean. The one has nearly lost the patch of fungus which is hanging off like it has peeled back. But he has developed black spots, first on his head and now on his body. He clamps hos fins when not swimming but is wobbly. The other looks better as it is no longer fuzzy but he is brown so I cant see ifd he has the same spots. I lost two other fish a while back. One, the same size as these, would lay upside down at the bottom. She did the same thing last year and I brought her inside. Once she warmed up she got better. But this ypar she didnt. The other one was smaller and I have no idea what happened to him. I have a little bitty fantail in the pond that seems to be fine. It’s just these bigger ones that are sick. We just had the well pump replaced and they put chlorine in it to clean it out, so I can;t change the water in the pond just yet. Plus it is too cold to do that. Any ideas what I have going on?

  7. I am desperate and want to see if I can save my tropical platty. She has been a fighter and but I have never seen what a think is a fungus before. It continues to grow all over but she has been a fighter and still eats in its quarantined aquarium. Not sure who I could send pics to too but want to try and save her.

    It is a white bubble type fungus that started on its side and then got became more rounded and pronounce. It is spreading still and I have tried salts and Pimafix with no luck. HELP!!

    Mark, if you are still here, I am sending an email with pics.

    • Thanks for your comment Hector. We follow up via email. I hope you can determine what it is. I provided two guessed based on the photos and video you sent over.

    • Hi Sylvia. They could be. Freshwater fish generally will eat plants because it’s part of their nature and diet to do so. You may have fish that do like eating plants. I would suggest getting plants that they are going to want to eat like Java Fern or Anubias. Can you tell me what fish you have? Freshwater fish are will just eat plants while saltwater fish may eat things like corals depending on their personality and food availability (which is why so many saltwater fish are listed as “with caution”).

  8. One of my pearlscale goldfish seems to be exhibiting unusual behaviour lately. He has been hovering near the surface of the tank (I don’t think it’s an issue with oxygen, because he’s the only one who swims up to the surface) or just swimming in place, barely moving. Even when he does move, it is rather slow. I’ve spotted him falling to his side before regaining balance a couple of times too. When it comes to his excretions, they are rather abnormal too. Once, his faeces couldn’t disconnect from his anus and it extended to about 3 or 4 times his body length. Now, he seems to be excreting white, stringy matter. I am suspecting constipation or swim bladder disease, but I am not exactly sure. Can you identify what’s wrong with him?

    • White stringy poop sounds like an internal parasite. I would recommend putting SeaChem Metro and Focus in food. Feed to the fish to remove the parasite. You may need to use a supplement like garlic to encourage the fish to eat.

  9. A couple of my cichlids have what seems to be a shrunken tail and tend to swim with nose elevated. I have a 180 gallon tank with only cichlids except for algae eaters. They all seem to be healthy (they have babies often etc) except the ones with the tail problem. Please let me know what this is.


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Cichlids are some of the most popular freshwater fish families in the aquarium trade, famous for their bold markings and colors, interesting behavior, and vibrant personalities. While many species have a reputation for aggression, one group of cichlids, the 'earth eaters' are known for their relatively peaceful temperament and amazing colors.
The 7 Best Plants For Cichlid Tank (That They Won't Eat)
Cichlids are aggressive towards each other, but are they aggressive to live plants? Most Central and South American cichlids can be kept with a variety of aquarium plants, but African species are more challenging to pair due to water parameters. It's not impossible though!
Why Angelfish And Guppies Are A Deadly Combo
You might think that guppies are easy fish that can be kept with nearly any other species, right? While these small, hardy fish can get along with most fish species, they are not compatible with angelfish. Keep in mind that angelfish are a type of cichlid, and so they should be treated as such.