Aquarium Salt for Goldfish – The 3 benefits of using salt in your goldfish tank

There are so many off-the-shelf aquarium medications available in the market nowadays, targetting the prevention or/and treatment of various problems that you may encounter in your goldfish keeping. Although these are very useful, they tend to be costly as well but there is a cheaper way: Aquarium Salt.

Aquarium salt for goldfish keeping has been widely practised by hobbyists for generations. Although it is not the miracle cure for all problems, they do serve as a cheaper remedy for the common ones.

Let’s take a look at what aquarium salt is, and what can it do for you besides NOT burning a hole in your pocket.

Aquarium Salt for Goldfish

What is Aquarium Salt?

Aquarium salt is different from the salt that you use in your kitchen for cooking. Although they are all Sodium Chloride (NaCl), aquarium salt does not contain any iodine or additives such as calcium silicate that exist in most table/cooking salt.

Aquarium salt is largely manufactured by evaporating sea water to get just the salt, and they can be found easily from your local or online fish stores.

What are the benefits of Aquarium Salt?

1) a source of electrolytes

Goldfish is a freshwater fish. Its body contains electrolytes which make it denser as compared to water in its surrounding. Due to osmotic pressure, the water from the surrounding gets pushed into the body in the attempt to “dilute” it. A healthy goldfish is able to regulate this by constantly eliminating water from its body through respiration and urine. (Yes! all fishes do urinate).

However… when a goldfish get stressed, this natural mechanism gets interrupted, causing it to lose electrolytes. Electrolytes in the body are very important for its gills uptake of oxygen and the emission of carbon dioxide and ammonia from the body. Losing electrolytes will pose very serious health problems for your goldfish.

By adding aquarium salt to the aquarium, it provides the additional electrolytes that the stressed goldfish needs, thus improving its breathing and elimination of wastes. This certainly helps the natural mechanism of regulating the water with-in and with-out the body to work again.

2) ENCOURAGES Slime Coat Production

If you have ever held a goldfish (or any fish) in your hands before, you will know how slippery it is. It felt as if it has a layer of slime on its body and that ladies and gentlemen, is the slime coat.

Slime coat is a mucoprotein coating on a fish body which acts as its main defense against infections and diseases by external organisms.

When your goldfish gets stressed, its immune system gets impacted and affects the production of slime coat. As you would have guessed, this will not end well as your goldfish is now exposed to external infections and diseases, which causes even more stress.

Aquarium salt in the water encourages the production of slime coat on your goldfish’s body so that the defense against external organisms continues to be up to prevent your goldfish from falling sick. This reduces the level of stress to your goldfish… and well, to yourself.

3) Weaken Pathogens such as Bacteria & Protozoan

Aquarium salt is also found to be effective in treating infections or diseases caused by pathogens such as bacteria and protozoan.

These bacteria and protozoan are simpler life form with no internal organs, unlike your goldfish which has a kidney. Because of this, they do not deal with the changing concentration of salt in the water as well as your goldfish. In such situation, these pathogens get weaken.

This is why aquarium salt can be used to treat infections and diseases such as the ick/ich.

How to use Aquarium Salt?

The benefits of using aquarium salt in your goldfish tank as mentioned above can be categorized into 2 types of uses against infections and diseases:

  1. For Prevention
  2. For Treatment

However do note that although you can use aquarium salt for goldfish, not all fish species can tolerate it. So please do your due diligence before using aquarium salt for other fish species. Also, most aquatic plants do not work well with salt.

1) For Prevention

There are 2 practices around adding aquarium salt for prevention purpose. The first is by constantly having it in the tank all the time, and the second practice is to use it only when required i.e. when quarantining a new goldfish or when there are early signs that the goldfish is stressed.

Goldfish Stress

Whichever practice you choose to follow, the dosage for prevention is half a teaspoon of aquarium salt for each gallon of water. Dissolve the salt in water before adding it in.

For me, I am more partial towards the second practice as I think goldfish should not be kept constantly with salt as it is not a brackish water type of fish.

Furthermore, I wonder whether having salt in the water all the time will build up the pathogens’ resistance towards it. If so, aquarium salt will no longer be effective in treating those infections or require higher dosage which will cause elevated discomfort to the goldfish.

Important note: If you have any goldfish that is stressed, you need to identify the cause and deal with that. Check out this post on the causes of stress and what you can do about them.

2) For Treatment

In the case of early stage or minor infection, the dosage to use is 1 tablespoon of aquarium salt for every 5 gallons of water.

Do a ~25% water change every 2-3 days and make sure you top up the aquarium salt accordingly based on the amount of water you are adding in.

In the case of major infection, you can put your goldfish through the dip method. This is actually upping the concentration of the salt and dipping your goldfish into it for a short period of time.

You will have to prepare a separate container and fill it up with some of your tank water. Then dissolve 4 teaspoons of aquarium salt for every gallon of water. After this is done, place the affected goldfish in for 30 minutes and then return it back to its tank (or ideally, the quarantine tank).


Aquarium salt is indeed the more natural remedy for most of the common infections that can happen to your goldfish. Although it can’t solve all of your goldfish keeping problems, it is very useful in preventing and treating them from common parasites.

Besides that, it is very easy to find and in case I did not say it enough, it is also cheap! To me, it is important to have aquarium salt for goldfish keeping.

Let me know your thoughts and your experience with using aquarium salt. Did it work for you?

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6 Replies to “Aquarium Salt for Goldfish – The 3 benefits of using salt in your goldfish tank

  1. You know what, that’s actually really interesting a lot of people get fish nowadays especially for their children and can never work out why the fish has passed away or why certain things have happened. This is really interesting!

    1. Hi Chantelle,
      That is true. Keeping fish or any pets in this matter require some basic knowledge & understanding on their care. It is also an on-going learning from our own and others’ experiences.

      This is why I started this blog, to share on my own goldfish keeping experience & the information that I have gathered along the way. Hopefully it will be of help to other goldfish keepers.

  2. Wow I never knew you could use salt with freshwater fish. I have been treating my water with the standard chemicals. As you say they can get pricey. Is this good for all freshwater fish or mainly goldfish? I have 2 tiger oscars. Will salt do the same for them or hurt them? Thanks

    1. Hi Jason,
      Generally scaleless fishes such as corydoras do not tolerate salt well. Other freshwater fish like your Oscars should do fine with the right dosage of aquarium salt.

      Thanks for the comment!

  3. this is very well written article on aquarium salt. it is easy to use for treatment and minor stage. i really enjoyed reading your article and i would be glad if you could visit benifits of aquarium salt thank you

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