Aquarium Salt 101: How Much Per Gallon for a Healthy Tank?

Last Updated on 2023-08-08

It may come as a surprise to freshwater aquarium owners that aquarium salt is actually good for their tanks. In reality, you must know why and when to use aquarium salt in your freshwater aquarium. The knowledge of this is essential for all fish keepers.

The health of your fish may benefit from using aquarium salts in a number of ways. Providing aquarium salts when needed is a crucial element of caring for your freshwater fish and ensuring their well-being. A lot of people who keep fish don’t know what aquarium salt is or how to use it effectively.

Keep reading to find out why aquarium salt is essential for the well-being of freshwater fish.

How Much Aquarium Salt Should You Use Per Gallon?

You can use as little as 1 tablespoon of aquarium salt for every gallon of water or as much as 2 tablespoons of aquarium salt for every gallon of water. Remember, though, that freshwater fish can’t handle very high concentrations of salt; thus, 1 tablespoon per gallon of water is already quite too much. You should gradually introduce salt to a fish that has been living in a salt-free environment. We recommend beginning with a concentration of no more than 1 tablespoon of salt per 3 liters of water. You should start with a low salt concentration and progressively raise it by a modest amount every week until you reach your desired level.

Aquarium salt is used in different ways and at different concentrations based on the aquarium’s needs. For instance, what you use for everyday use and disease prevention won’t be the same as what you use for curing a disease.

Let us take you through each of these instances individually:

Use on A Regular Basis or For Disease Prevention

Salt therapy is widely used to treat a variety of illnesses, but it also serves as an effective preventative precaution. This is why it is popular among aquarium keepers. It’s completely organic, harmless, and beneficial to your fish.

It is suggested that 1 tablespoon of salt be added for every 5 gallons of water as a preventative measure. That concentration works great in both saltwater and freshwater aquariums.

Treatment of Diseases

Here is where extra caution is required. Aquarium salt treatments typically involve three doses given at regular intervals. Aquarium salt dosage is increased progressively to cure aquatic infections and diseases.

First Dosage

Aquarium salt can be used as a treatment for several diseases, but it’s best to start with a low dosage of 1 tablespoon per 3 gallons of water. A concentration of salt this low is believed to be harmless. There are a few species of catfish that can’t tolerate this much salt, but otherwise, most freshwater fish will be fine. If your symptoms haven’t improved after a week on the current salt regimen, you might want to try increasing it.

Second Dosage

If the initial dose of aquarium salt does not alleviate the symptoms, try increasing the salt concentration to 1 tablespoon for every 2 gallons of water. Diseases like ich should be effectively treated at this dose. If the symptoms have not improved after a week, though, you may want to try taking more salt.

Third Dosage

A higher quantity of salt (one tablespoon of aquarium salt for every gallon of water) may be necessary if the symptoms do not subside after the second dose. Bacterial, fungal, and external parasite problems of various types will be addressed at this level of care. This, however, is a lot of salt for a fish that normally lives in freshwater. At this concentration, the treatment may be more effective, but it may be too strong for some fish to tolerate.

Catfish and other fish without scales may not be able to tolerate this much salt. Danios, tetras, silver dollars, and livebearers are examples of salt-tolerant fish species.

Keep a close check on the fish as they undergo a salt treatment. In most situations, the ability to observe is crucial. So long as the fish are still not doing better, keep the salt in the tank. To get rid of the salt in the aquarium once the fish has recovered, you can make water changes of up to 30 percent every week. When the salt is no longer present, the sickness may reappear. If the illness reappears, the salt intake must be brought back up to normal levels.

image of aquarium tank with a variety of aquatic plants inside.

Symptoms Of Too Much Aquarium Salt

Whether you’re just starting out or are a seasoned marine life expert, it’s important to have a firm grasp on the salinity levels at which certain aquatic species thrive.

So, killing the fish in your aquarium by dumping too much salt into it is a bad idea. In contrast to what one might expect, fish will perish from dehydration due to excessive salinity rather than benefiting from it and being able to fight off diseases.

This is why it’s crucial to keep a close eye on your aquarium during the salt treatment, according to aquarists. If you really care about the fish, you’ll want to account for every conceivable change in its characteristics. If they were previously active but are now silent, this could indicate a salt imbalance.

Do not give the fish any more salt if it shows no signs of improvement after three treatments. We suggest keeping a watchful eye out for signs like:

Infrequent Swims

Too much salt in the aquarium might be bad for the fish. Over time, an excessive amount of salt in the tank might disrupt their osmotic balance and irritate or injure their gills, which can manifest as a lack of swimming activity. Too much salt can have extremely significant implications; therefore, it’s crucial to keep an eye on the salinity level and make the necessary adjustments to keep your fish alive and thriving. There should be an immediate action taken if any unusual conduct is observed.

Indifference or Lethargy

Fish that have been exposed to excessive amounts of salt from an aquarium may become unmotivated and uninterested. Too much salt in the fish tank might cause abnormal behavior like decreased hunger and indifference. Salt levels in a tank should be checked before any more is added. If the concentration is too high, the fish’s respiratory system may become overworked, and they may have trouble breathing. Keep an eye on those levels and err on the side of caution when adding aquarium salt; doing otherwise may cause the fish discomfort and even serious health concerns.

Poor Appetite

When fish stop eating as much as they usually do, it may be because they have been subjected to high levels of salt. While other factors, such as temperature and water quality, should also be considered, a fish that isn’t eating may indicate that you need to lessen the quantity of salt in its tank. A trip to the vet is in order if this issue has persisted for some time.

Going to The Bottom of The Tank

Since salt water has a higher density than freshwater, one of the most obvious signs is when your fish begin to sink to the bottom of the tank. It’s important to keep an eye on this conduct and make any necessary adjustments. If you’re not sure, use a particular gravity meter to make sure, or cut back on the salt.

Infections of The Skin, Etc.

One of the most common and clearly observable indications of too much salt in an aquarium is skin irritation or infection in the fish. If the salt concentration is too high for a given species, it may experience discomfort or inflammation at the affected location. Also, in extreme circumstances, it can cause other types of damage, such as clouding of the eyes.

Tanks with scaleless fish are especially prone to skin problems. Excessive salt might cause the fish to develop red spots or lesions all over its body. The aquatic plants that live in the aquarium with the fish are also negatively impacted by too much salt. So, remember to watch the vegetation as well.

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How Much Aquarium Salt per Gallon for Bettas?

Bettas, and animals of other species, can benefit from it in a number of ways that make life easier for them and protect them from illness. The most important thing is to use it properly, as directed, and not to use more than 1 tablespoon for every 5 gallons.

How Much Aquarium Salt per Gallon for Goldfish?

To keep your goldfish healthy, add half a teaspoon of non-iodized salt for every gallon (4 liters) of water or one teaspoon for every three gallons. A separate treatment tank with one full teaspoon of salt per gallon of water is effective for treating goldfish infections without risking the loss of plants, beneficial bacteria, snails, or shrimp that should not be brought to a treatment tank.

How Much Aquarium Salt per Gallon for Fin Rot?

Aquarium salt can be used to treat minor cases of fin rot at a rate of 1 tablespoon per gallon of water and more severe cases at a rate of 2 to 2.5 tablespoons per gallon of water.

How Much Aquarium Salt per Gallon for Hermit Crabs?

Aquarium salt is often used by keepers of hermit crabs as a substitute for sea salt in the saltwater they provide their crabs. Half a cup of aquarium salt should be diluted in one gallon of water. You need to mix everything together until the water is clear.

How Much Aquarium Salt per Gallon for Brine Shrimp?

The saltier, the better for brine shrimp. Their ideal sp ranges from 1.024 to 1.028. That’s slightly more than 1.5 Tablespoons for each liter (or quart) of water. A salinity of 1.018 can be achieved with 1.5 TBSP. Brine shrimp salt can be regular table salt without iodine.

How Much Aquarium Salt for A 10 Gallon Tank?

Whether or not an aquarium needs salt to function depends on the reason for doing so. About 2 tablespoons of salt per 10 gallons would be necessary if you want to add it for a common purpose and disease prevention.

Can Too Much Aquarium Salt Kill Fish?

Most aquarium fish and snails will die if too much salt is added to the water. Fish will often lose their appetite, swim erratically, and appear anxious as they swim frantically near the surface, panting for breath. A layer of slime will form on most fish, and they will become dehydrated and die from it.

Should You Add Aquarium Salt for Every Water Change?

Always add salt to the aquarium’s new water after any treatments or supplements have been added during a water change. To a water volume of 1 gallon, dissolve 1 level tablespoon of aquarium salt.

How Fast Will Aquarium Salt Kill Ich?

After about a week, most fish will begin to show signs of improvement. You can get rid of the ich in 7-10 days if you use the right dosage of aquarium salt for the prescribed amount of time.


As we have learned in this article, aquarium salts can be very beneficial for your fish tank. It is generally recommended to use one tablespoon for every 5 gallons of your tank, but the amount still varies depending on your aquarium’s needs. Whether it’s for disease prevention or curing, using the proper quantity is crucial. And if you notice symptoms of too much aquarium salt during the treatments, take the necessary actions right away.

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