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Using Salt in Freshwater Aquariums
Freshwater Fish Tank

Using Salt in Freshwater Aquariums

There are many benefits to using freshwater aquarium salt in your freshwater aquarium! Although it is made from evaporated sea salt, it is not the same as the salt used in marine aquariums. Don’t be salty though, let’s dive into the benefits and uses of this natural supplement to gain a better understanding of how it could help improve the overall health of your aquatic life!

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This all-natural salt is made from evaporated sea water and promotes healthy gill function while reducing stress and the loss of electrolytes. Additionally, it promotes your fish’s slime coat and can even help heal wounds. 

Freshwater aquarium salt can assist with some parasitic infections and will help improve the efficiency of medications. In addition to the medication, salt can be utilized for baths or dips to combat external parasitic infections. Baths and dips are a little different than the salt levels maintained everyday within the aquarium.

Imagitarium Aquarium Salt

Ways to Use Salt in a Freshwater Aquarium

Salt Bath

For a bath, you need to utilize one teaspoon of freshwater salt per gallon of aquarium water. This is dissolved in a separate container, then slowly poured into the aquarium. This treatment is typically maintained for three to four weeks. If utilizing the bath treatment, you will need to complete weekly water changes of at least 25% to slowly reduce the salt content, preventing shock to the fish.


With a severe parasite infection, a dip may be needed. A dip is a little different than a bath and as the name implies will be performed outside the aquarium in a separate container. For this, you will completely dissolve 5 tablespoons of freshwater salt in a container containing a gallon of aquarium water prior to introducing a fish. The fish should be placed in this salt-heavy water for minimum of 5 minutes however, it can be extended to thirty minutes if the fish is not showing signs of stress. If the fish is showing any signs of stress, like laying on its side, immediately return it back to the aquarium.  Be sure to dispose of the dip solution- do not pour it into your aquarium.

Reducing Nitrite, osmotic stress and maintaining effectiveness

Nitrite becomes toxic to fish at a concentration of 0.1 ppm (part per million). The chloride in the salt can help to reduce the toxic effects of nitrite on aquatic life. Due to the concern of nitrite poisoning, salt can be extremely beneficial during the cycling period in a new aquarium setup, inhibiting nitrite intake.

A fish’s body is continuously busy with osmoregulation. This is the process of maintaining the internal balance of salt and water, therefore aquarium salt may also assist with reducing some osmotic stress. 

For aquarium salt to be most effective, its generally recommended to dose after starting up a new aquarium and every time you complete a water change. Remember, salt does not evaporate, so it is imperative to conduct regular water changes and monitor specific gravity levels to ensure you do not accidentally accumulate higher salt concentrations within your tank.

Freshwater Aquarium Salt Dosage

While the most common dosing for pure freshwater aquarium salt is, 1 tablespoon per every 5 gallons, dosing should be done according to the instructions of the individual manufacturer. Some may give separate directions for preventive care vs treatment of an identified concern. 

If you are unsure of how much salt is in your aquarium, especially after a water change, the use of a refractometer is the most precise way to measure the specific gravity in your aquarium. 

Remember, for the health of your aquatic life, changing water parameters should be done gradually so be careful not to change your specific gravity more than 0.001 in a 24-hour period.

Even though this product is natural, caution should be taken as certain species of fish, especially scaleless fish, and plants are very sensitive to the effects of increased salinity in their habitat. It is best to follow the directions on the product, confer with your local aquatic specialist or reach out to the manufacturer’s customer service line if you have any questions.

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