Bath Treatments for Sick Goldfish

Bath Treatments for Sick Goldfish

A bath treatment is one the easiest delivery methods for treating a sick goldfish. These methods have been used to treat sick goldfish for as long as goldfish have been kept as pets. On the market today there are dozens of formulas that are used to treat all kinds of diseases. Each formula varies in its effectiveness; some work very well while others may be pointless. It’s important to use the appropriate method for the current situation.

The main concern about using bath treatments to cure a unhealthy goldfish is that the antibacterial medications usually tend to be hazardous to the biological filters, aquatic plants and even other fish that are not sick. Most options will then require the biological filter to be bypassed and thus sparing the beneficial bacteria. In most cases the filter media can be removed and placed into a bowl of tank water while the bath is in progress. This is easier said than done if an under gravel filter is being used. Attempt alternative cure before destroying the beneficial bacteria; this can create poor water quality and make matters worse for the ill goldfish.

Get this medication to treat:
fungus, mouth fungus, body slime & eye cloud, fin & tail rot

Get this medication to treat:
parasites, flukes, velvet, fish lice, hole-in-the-head disease


A powerful dye.

Treats: several types of ciliated protozoan, fungus, lymphocytes, Oödinium (Velvet) and Hexamatia.

Aquarium Salt

The most common and cost affective baths for treating sick fish. Aquarium salt does not include any iodine or calcium silicate and it won’t change the pH or hardiness of the tank water. It can harm some aquatic plants or certain fish species (not goldfish).

Treats: Ich, Chilodonella, Costia, Epistylis, Trichodina and helps reduce osmotic pressure of fish with body sores or swim bladder issues, popeye or dropsy.

Chloramine T

Also known as N-chloro-para-toluene sulfonamide is a quaternary ammonium compound that’s available in powder form or a product called BGDX by Argent Labs. If overused, it can cause caustic burns on the skin of the goldfish.

Treats: Bacterial gill disease.


Only use a chelated ionic copper of free-form copper to treat sick goldfish. High levels of copper is toxic and an overdose can kill a sick goldfish.

Treats: Bacterial gill disease, Chilodonella, Trichodina, flukes and Oödinium.


An insecticide that is normally used against gypsy moths. It’s a powerful insecticide and the EPA restricts its use.

Treats: Argulas, Lernea and Ergasilus. (fish lice, anchor worm, gill maggots)


The pill version of a tapeworm medication for dogs called praziquantel. It’s available through veterinary channels

Treats: Flukes and worms.


Also known as Methonidazole. Not as harmful to beneficial bacteria as other cures.

Treats: Hexamaita and Spironucleus.

Fluke Tabs

By Product labs. If left in the water for more than 48hrs, sick goldfish can get inflammatory dermatitis, a redness of the skin.

Treats: Flukes.


Essentially a formaldehyde gas in water and sometime mixed with methanol. If a white precipitate forms on the bottle, don’t use it. This is very toxic goldfish. Add extra aeration. Never use in water above 80*F (27*C). Can cause burns on long finned goldfish.

Treats: Fungi, some bacterial infections and most parasites (not ich or flukes).

Furazone Green

It’s made in capsule or powder form and readily available at pet stores. Contains furan antibiotics and methylene blue. Furans are carcinogenic and great care must be taken when handling.

Treats: Bacterial infections that respond to antibiotics.


A broad spectrum antibiotic for treating gram positive and gram negative bacteria. Less harmful and more affective than Maracyn Plus.

Treats: Fish TB, Dropsy and popeye.

Malachite Green

Treats: ciliated parasites: Trichodina and Costia. Topical fungal treatment.

Potassium Permangantate

A caustic alkali made in powder, granular or liquid form. Can dye skin and other surfaces that are difficult to remove. Harmful to eyes; wear eye protection.

Treats: Flukes, fungus infections, bacterial gill disease, bacterial infections of fins/body and ciliated parasites (not ich).


Brand name for lufenuron. Also named Larvadex. Inhibits chitin (skin) production, thus killing the crustaceans.

Treats: Argulas, Lernea and Ergasilus. (fish lice, anchor worm, gill maggots)


Levamisole phosphate that’s available through veterinary channels. It’s safe for sick goldfish and biological filters.

Treats: deworming medication.

Epsom Salt

Magnesium sulfate.

Treats: Helps reduce osmotic pressure of sick goldfish with body sores or dropsy.

Pond Healthguard

By SeaChem Labs. Less harmful than formalin. Add extra aeration.

Treats: Flukes.

Reviewed By: Tim Winter

Tim Winter has a strong affection for pets and wildlife. His years of experience caring for various types of pets has led him to share his knowledge with others on the best practices in pet care. Tim holds a Bachelor of Science from the University of Oregon School of Journalism and Communications.

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14 thoughts on “Bath Treatments for Sick Goldfish”

  1. my shubunkin goldfish has a protruding black growth around his eye and it is getting bigger, i am worried he won’t last through the night, I have the other posts and will check the ammonia and ph. He is floating around and not looking so good, he is 14 -15 years old and rather large. We moved about a month ago and I wonder if it was just too big of a change at his old age.

  2. My large goldfish first had a black spot on the middle of his upper spine, the spot appears to be gone but now he has two green fungus looking patches in the same area on his upper back. Ive read about fungus care products but I’m concerned about the other fish and the health of the pond. I also dont have another tank I could treat the sick goldfish in – is it ok to treat the entire pond water?

  3. For anyone reading this, be careful about using aquarium salt. If your fish is showing dropsy symptoms, it can make the bloating worse. Please do thorough research before making any decisions. Don’t be like me and regret it later.

    • What types of symptoms are your fish displaying? If you need immediate help, try going to the pet store and asking the fish expert. They should have the medications you might need.

  4. My goldfish is acting kinda weird right now. He’s not moving much (new tank, I understand that), but now he’s shaking his head back and forth and spitting out his food. He also keeps pulling his top fin down closer to his body. Is something wrong or is it just the stress of a new environment?

    • clamped fins can be a sign of several things, bacterial infections, parasites or poor water quality. I would first test the water for ammonia and change the water if the it’s high. A loss of appetite is another sign of the start of ammonia poisoning. If the water change doesn’t help after a day or so, try using a bath treatment of a broad spectrum anti-bacterial medication and some aquarium salt.

  5. I had won a fish from a state fair three weeks ago. At first I had him in a glass fish bowl and have just moved him into a 10 gal. tank. I just notice that the tip of his tail looks a little strange. I am afraid that it could be a bacterial infection. I don’t have a water pump yet so I have been cleaning his water and putting in fresh new water every other day. He moves around a lot and I think he has adjusted to the tank. My question is how do I know for sure that he has a bacteria infection? I have never own a fish before. So I don’t want to jump to conclusions and try to treat him and end up killing him.

    • I would observe the goldfish for a few days. if the fins get worse, you should treat it for fin rot or another infection it might have. When you change the water, if you use tap water, make sure you are using a dechlorinator. if the tail looks black or white, it could also be a sign of poor water quality. It might be ammonia burns. I suggest buying an inexpensive test kit to see if your water has the proper ammonia levels.

    • If it’s a new goldfish, it might take some time to adjust to its new aquarium. By giving it some places to hide, it might make it more comfortable and more active. You should also buy aquarium test kits to check for ammonia and aquarium pH levels. If those are off, your goldfish could become sick and die. You can also take a look at the section on goldfish diseases in goldfish aquarium care if the test come back normal.

  6. One of my goldfish is not moving.Well,a bit.But I am very worried.I have a how to take care of a pet goldfish book,I checked if it was healthy and it was.The air pump is on,my parents tried feeding it but it would not eat or move.


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