Epsom Salt Aquarium Dosage – Useful Information For Fish-Lovers

Magnesium sulfate, a substance made up of magnesium, sulfate, and oxygen is most well known by the term “Epsom salt.” 

Have you noticed that Epsom salt includes no sodium despite its name? As a result, it is not salt in and of itself.

Do you want to discover how it treats fish and how much Epsom salt aquarium dosage is necessary? Keep on reading!

What Is Epsom Salt?

Magnesium, oxygen, and sulfur are the three elements that makeup Epsom salt, sometimes referred to as magnesium sulfate. It was initially uncovered in Epsom in the county of Surrey, England, hence its name.

Epsom Salt

You can put Epsom salt into freshwater tanks to change the water’s chemistry. It is safe for pets in aquariums because it lacks the components present in sea salt. 

It is not processed like table salt or fish salt, which lessens its abrasiveness in the surrounding water. The aquarium’s Epsom salt can treat ascites, bladder issues, and constipation.

What Is Epsom Salt Aquarium Dosage? What Does It Use For?

The ideal formula for an Epsom salt aquarium is 1/8 teaspoon of Epsom salt to 5 gallons of water. This ratio is for long-term treatment. If you want a short-term remedy, 1 tablespoon of salt for 1 gallon of water would suffice for a 10-minute bath.

By creating this mixture, you can help your fish with the following diseases:

angel fish

Increase Water Hardness

Epsom salt can be utilized to make aquariums’ water harder, which facilitates some kinds of fish. Compared to soft water, hard water has more absorbed magnesium and calcium. 

The amount of hardness impacts the pH of the aquarium. In comparison to soft water, the hard type seems to be more alkaline. The quantity of calcium carbonate (CaCO3) in water describes its hardness. 

According to the Aquatic Community, Epsom salt can continuously raise water quality to roughly 70 mg/L CaCO3 by adding 1 ml per 10 gallons of water. 

Before making any tank chemistry changes, ascertain the ideal pH and water quality for the fish species in your tank. 

Fish can be stressed and even killed by an abrupt pH change, so keep pH changes to a minimum of 0.3 daily.

Constipation Treatment

Many fish get constipation regularly, including bettas. Fluid retention and a decreased appetite are symptoms. 

Overeating or a diet deficient in fiber are common contributors to constipation. Stop feeding the fish in this state for the next 24 to 48 hours. 

Provide the fish with small chunks of the interior of fresh or frozen peas instead of canned beans since they are excessively salty if you don’t notice a difference. 

If the fish’s condition does not better, think about giving it an Epsom salt bath to help relax its muscles.

Ascites Treatment

The kidneys of fish fail due to insulin resistance, leading to swelling of the belly of the fish with ascites, and their scales rise, which can be deadly. 

By putting sick fish in a separate “hospital” tank and adding Epsom salt, you can help reduce swelling. 

We also recommend feeding your fish a special diet containing antibiotics. 

Never cure ascites in fish with aquarium salt or any other sodium compound, as doing so can aggravate the problem.

Bladder Disorder Treatment

All freshwater fish can develop swim bladder disorder. However, goldfish are more prone than others. 

Due to the existing injury to the bladder, which is often stuffed with air, fish with this ailment have trouble swimming upright. 

The causes of swim bladder diseases include taking in too much air, breaking an egg, infection, and constipation. 

For 2-3 days without sucking, treat a bladder issue by giving the baby some shelled peas. 

If this does not work, raise the water’s temperature in the aquarium between about 78 and 80 degrees Fahrenheit and add Epsom salt at 1/8 teaspoon for every 5 gallons of water.

How To Make An Epsom Salt Bath?


Follow these steps to create an Epsom salt bath:

  • First, prepare a separate tank. Pick one that has a minimum capacity of one gallon. Depending on the necessity, one tablespoon of Epsom salt per gallon of water is the recommended dosage for this aquarium. 
  • Then, it would help if you let the water fully absorb it.
  • Next, set up another freshwater tank for the fish to revive after the bath. Fill it with one-fourth of the cleaned Epsom salt water and three-fourths of the freshwater. 

Place the fish in the Epsom salt aquarium after taking it away from its original tank. Let them take a bath for about 10 minutes. Watch out for your fish during the Epsom salt soak to prevent fainting or jumping out of the aquarium.

  • Move your pets to the revival aquarium when the therapy is finished. 

This step is significant because it will give your fish time to adjust to less salty surroundings before reintroducing them to the aquarium’s regular water column.

  • It’s time to leave the revival tank after a short while. Move your fish with care from that tank to their original aquarium. 

Don’t forget to keep an eye on it for a while to ensure it adjusts once more.

What Are The Differences Between Aquarium Salt and Epsom Salt?

Aquarium salt mostly contains sodium and chlorine. Meanwhile, Epsom salt is sodium-free.

Aquarists should avoid using aquariums or table salts if they are uncertain about fish sickness. Consumption of salt can make things worse. 

However, fish are not harmed by Epsom salt. You can employ this salt to ward off illness. 

But on the day you add Epsom salt to the water, be cautious not to feed them any food.


A chemical substance called Epsom salt is used to treat fish with constipation, swim bladder illness, and ascites. We must therefore acknowledge that it has a variety of purposes.

We sincerely hope our post on Epsom salt aquarium dosage was useful to you. Do you have any other queries or remarks? Comment in the box provided below!