How Much Epsom Salt Should You Use for Treating Dropsy Disease in Fish

Typically affecting goldfish and freshwater fish, dropsy is one of the most common problems aquarium owners have to face. While identifying the exact cause of dropsy can sometimes be difficult, treating the symptoms is not.

Fortunately, Epsom salts are a safe and effective treatment for dropsy in fish that owners can use themselves. It’s important to use the correct amount however and avoid some pitfalls in order to properly care for your fish.

Below, we’ll explain when Epsom salts should be used to treat dropsy and exactly how much you should use.

Identifying dropsy

Firstly, it’s important to make sure you’ve correctly identified dropsy in your fish. While Epsom salts are safe for your fish, you don’t want to be putting them through additional stress unduly.

Strictly speaking, dropsy is the name of a set of symptoms rather than a causal disease. Nevertheless, the term is used by aquarium owners to refer to bodily and behavioral changes caused by issues such as poor water conditions, prolonged stress, parasites, bacterial infections, or kidney failure.

The symptoms themselves are fairly numerous but the most common sign of dropsy is an abnormally swollen abdomen in your fish. You may also notice the fish’s eyes and scales begin to protrude too. This is because the fish is retaining an extreme amount of fluid.

Most commonly cited symptoms are:

• Swollen abdomen
• Protruding eyes and scales
• Colorless gills
• Fins clamp to the body of the fish
• Spinal curvatures
• Pale excrement
• Anus swelling
• Loss of appetites
• Low energy and reduced movement

While dropsy can be treated, if your fish has got to the point where its body is largely swollen and scales are protruding in a pinecone-like fashion you will need to act fast. The pressure from the retained fluid is likely affecting the fish’s internal organs and is likely to be causing it considerable distress.

What is Epsom salt?

Epsom salt is the common name for Magnesium Sulphate. It is a naturally occurring mineral compound that is named after the town near London where the salt was first popularized.

Unlike table salt, Epsom salt is essentially inedible. While it’s not strictly toxic in small quantities, it is extremely bitter to taste and is only really suitable for health and wellbeing treatments such as dissolving in baths.

Epsom salt is water soluble and features a large and clear crystal formation. It will not feel as gritty to the touch as table salt with some even describing it as a feeling “oily.”

How does Epsom salt work?

As with all salt, Epsom salt is good for dehydrating. When added to an aquarium, Epsom salt can help pull fluids out of infectious parasites, fungi, and bacteria that could be causing dropsy in your fish. This causes them to perish and helps treat the cause of your fish’s dropsy.

It also helps reduce the swelling in your fish through the same effect, drawing moisture out of the fish. While this may sound detrimental, low dosages of Epsom salt will not harm your fish and will, instead, alleviate their dropsy symptoms.

The result is your fish shedding the excess fluid and returning to their proper size.

Other benefits of Epsom salt for fish

In addition to treating dropsy, Epsom salts have the added benefit of treating the following too:

• Constipation – When bloated from dropsy, fish can also find it difficult to excrete. Epsom salts can help act as a mild laxative, loosening stool in the fish’s digestive tracts and allowing them to pass their feces more easily.
• Swim bladder disease – Another issue that can be treated with Epsom salt is swim bladder disorders. This is where the swim bladder which is normally inflated with air fails to function correctly, causing the fish to swim sideways or cannot swim upright without effort. Epsom salts can help treat the infection and constipation that is often the cause of swim bladder disease.

Epsom salt dosage for dropsy

While a lot of owners and manufacturers disagree on the correct dosage of Epsom salt to treat fish with dropsy, a general consensus has been found.

The amount of Epsom salt you need to use will depend on whether you are treating an entire tank or giving an individual fish a concentrated bath.

Applying Epsom salt to aquarium directly

You can add Epsom salt directly to your aquarium to treat dropsy. This is useful if more than one fish in your aquarium has dropsy or if you feel the stress of removing the fish from its environment is going to cause too much stress.

While Epsom salt is safe to use, it’s important to not add too much to your tank, so measure using adequate tools.

For treating a tank directly, add ⅛ teaspoon per 5 US gallons of water.

Metric: 0.75 grams per 20 liters.

Concentrated Epsom salt bath

For more severe cases you may want to try a concentrated Epsom salt bath where you take your fish out of its tank and let it bath separately in a higher dosage.

For this, you will want a clean plastic container into which you should add 1 tablespoon per US gallon of water.

Metric:14 grams per 3 liters.

Submerge the fish in this concentrated bath for 5-10 minutes. Larger fish will be ok for up to 15 minutes but this should be considered an upper limit. Be sure to reacclimatise your fish before returning it to its aquarium and try and match water temperatures to prevent thermal shock.

Frequently Asked Questions

Is aquarium salt the same as Epsom salt?

Epsom salt is not aquarium salt, the two are considerably different and are not equivalent.

Aquarium salt is sodium chloride which is what we commonly refer to as salt. This is unsuitable for freshwater fish and goldish as it creates a saline environment that is unsuitable for them. Epsom salt differs in that it is a salt without the elements that are harmful to these fish.

Can I use any Epsom salt?

Not all Epsom salts are suitable. Some are perfumed and contain fragrances that are suitable for human use as a relaxation treatment. These and any other Epsom salt with chemicals in should not be used as a treatment for dropsy as it will harm your fish.

Is Epsom salt safe?

Epsom salt is 100% safe as long as you use it correctly (short concentrated bath or properly diluted in an aquarium) and it contains no added chemicals or fragrances.