top of page

Salt In Freshwater Aquariums | Adding Salt To Your Freshwater Fish Tank

Updated: Oct 23, 2020


Salt can be an excellent product to help with the treatment of bacterial, fungal, and parasitic infections. Some people will use it in conjunction with medication, and others will use it instead of medications.

One of the nicest things about salt is how readily available it is and how low the cost is compared to many of the medications available. There are also many people in the hobby who prefer to only use medications as a last resort and wish to use a more natural approach whenever possible.

Types of Salt and their uses

Aquarium salt or sodium chloride can help with replenishing electrolytes, assist with gill function, and is a common treatment for parasites, fungal infections, and bacterial infections.

Epsom salt or magnesium sulfate acts as a mild laxative and muscle relaxant which is used most often used for fish that are egg bound, have swim bladder problems, dropsy, or are experiencing digestive problems. When using Epsom salt be sure to get plain Epsom salt as you would not want to accidentally use something like lavender Epsom salt in your aquarium.

There are many other types of salts available, but some contain minerals or additives that may not be safe for fish or they could cause problems with increasing your TDS or PH in the tank.

Recommended dosages and treatments using salt can vary depending on the species and illness you are treating, so always be sure to research the species you are treating as well as the illness before dosing with salt.


  • Some species can be very sensitive to salt such as catfish, loaches, snails, and aquatic plants, and some invertebrates so always be sure to do your research on the species you are keeping in your aquarium before adding salt to your aquarium for treatments.

  • When using salt to treat your fish, you will often want to start with the lowest dosage to see if this will take care of the problem first. Some fish can handle larger doses of salt than others, so often the lower dosage will be safer for the fish.

  • When choosing salt know that finer grained higher quality salts will dissolve faster and usually have less contaminants than the larger grained rock salts.

  • When adding salt into the aquarium it is important to know that salt does not evaporate from the tank and will not be removed through filtration. Salt can only be removed through water changes. After the initial dose of salt into your tank you will only want to add salt back into the tank based on the amount of water being replaced and not the total volume of water in the aquarium.

  • Before adding salt to your aquarium, it is best to dissolve the salt in a separate container to prevent fish from coming into direct contact with the salt which could cause salt burn on the fish.

*This post contains affiliate links*

8 views0 comments
bottom of page