Dips and Baths

Treatment: Dips and Baths

By Gary Hater

Treatment of goldfish that are ailing from flukes, protozoans, fungus and bacteria has changed over the last two years, most of our historic treatment chemistries and medicines have become unavailable under most conditions. Regulations require collaboration with a veterinarian in order to get medicines. For internal issues, we must go to the Vet, but for gill, skin and fin issues, dips and baths often offer a quick and inexpensive methodology.

Dips and baths are designed to do one of two things; kill the microbe or get it to jump off the host. The collection of ingredients are pretty easy to find and in most cases, do not damage the fish if instructions are followed.

The primary option for ingredients include the following;

Salt (any salt that is non-iodized, the trend with large hobbyist is to use rock salt meant for water softeners – Solar Salt Brand).

Potassium Permanganate

Hydrogen Peroxide (3%)

Methylene Blue

Formalin (10%) or Formaldehyde (37.5%)

Ich Medicine (containing malachite Green and formalin)

Two cool books, both out of print, have a few dip references;Health Care Standards for Goldfish and Koi – by JoAnne Burke, 1995 (initial owner of Dandy Orandas and Fancy Goldfishby Erik Johnson and Richard Hess, 2001.

Why dips and Baths?

Dips and Baths are used instead of treating the entire tank or pond in order to save money and to prevent damage to the nitrogen cycle and the live plants. Often the initial reaction is, but what about the tank? The reality is that the majority of the critters on the fish are only on the fish. If you are concerned about the tank a light dose of salt (1 tsp/gal.) or a short peroxide treatment (3%) of 2 ml per gallon of water for two hours prior to a 50% water change should help to manage this. Note the hydrogen peroxide will inhibit the nitrogen cycle for a day or two but will not do permanent damage.

The baths and dips are generally made up of water from the tank with the troubled fish. You can do this easily or you can do treatments with fresh water, but then you must check the temperature and pH.

Figure 1: Key reference books by Jo Anne Burke, Erik Johnson and Richard Hess.

The following dips are based on our experience and knowledge from the above these books and sources. Use them at  your own risk, if the fish is misdiagnosed, too sick or the treater is not paying attention, you will possibly euthanize the fish.

Hydrogen Peroxide Dip

Flukes and protozoans in the gills and the body are often killed or knocked off the fish by peroxide treatment. Take eight (8) quarts or liters of tank water and mix with one (1) quart /liter of over the counter 3% hydrogen peroxide. There are 3.785 liters to a gallon, so mixing the terms in this case makes no difference. Add the fish for 10-20 seconds, if stressed remove it. It is best to use your hands instead of a net so the knocked of critters do not end up in your net. You can use several fish in this dip, but the dip loses potency in a matter of hours because the hydrogen peroxide dissociates into water. Conceptually this may help bacteria and fungus issues, but it is not fully tested.

Potassium Permanganate Dip

This dip is used for flukes, protozoans and general lethargy (no clue what it is). The great thing about this dip is that you can leave the fish in it for a good while (up to an hour) and if the purple solution turns brown and the fish is not stressed you can add another dose.

A great reference exists on the TheGoldfishCouncil.org under articles called the “The Power of Purple”. Potassium Permanganate is a strong oxidant that stains hands and clothing. It is typically bought as a powder. The stock solution uses a 2 Liter soda bottle filled with distilled deionized water from the grocery store and a level tablespoon of the powder. This is the stock solution that will keep for months if not exposed to sunlight. Typically, 10 gallons of tank water is mixed with 25mls of stock solution (5 teaspoons). This treatment can be repeated for several days.

Salt and Methylene Blue

This dip is great for Costia, fungus and bacterial slimes on fish. It is relatively mild and can be used several days in a row. The methylene blue is a stain that enters the cells of protozoans, funguses and bacteria and prevent replication. Because fungus and bacteria are typically layers of cells multiple daily treatments are often recommended. Use three (3) teaspoons of salt per gallon of dip container and one (1) teaspoon of methylene blue per three gallons of dip water. Typically, the fish are added for 30 minutes. Avoid using a net to move the fish unless it is too big.

Protozoan bath (formalin and malachite green)

This formulation can be used as a dip or bath for treatment of protozoans other than Ich.

 The treatment as a bath is fairly mild, treated in an aerated container you can leave the fish in it for as long as eight hours. Dose according to instructions on the label. This is not for treatment of Ich

Formalin (10%) or Formaldehyde (37.5%)

Used to keep fish from dying from secondary bacterial infections related to poor water quality and over feeding.

Generally used without malachite green for treatment of small fish <1”).  Formaldehyde is one (1) ml per ten gallons.  The fish are typically left in this water for hours, until their grow out tank is cleaned by siphoning of the bottom and doing at least a 50% water change

 Mega Salt Dip (Caution)

Treats Praziquentel resistant flukes and heavy Costia and other heavy protozoan infestations. Often used after other things just do not work.   

Mega Salt Dip (Caution) continued…

This technique is referenced in the Jo Ann Burke text and is published in the state of Indiana for the Aquaculture industry.  The dip is short, it is lethal for fish that are already very weak. In a five-gallon bucket add four (4) gallons of water, then add 2 cups of salt. Stir and dissolve the salt.  Add one or more fishes for a maximum of 20 seconds, if the fish rolls over or quits breathing remove immediately. After removal, you should swish the fish back and forth in its’ home tank to get fresh water over the gills. Never put fish in this treatment and take a phone call or text, you will kill the fish.

Dips are designed to save fish without ruining your nitrogen cycle, killing your plants and treating unknown problems with short term care. There are many people on The Goldfish Council board that can help with these techniques. Get some help easily on the Goldfish Council – chat.

Thanks for reading,

 Gary Hater

Founder –  The Goldfish Council