Using Aquarium Salt For Betta: Can It Heal Or Kill?

aquarium salt for betta
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Last Updated: August 22, 2023 by Flora Gibbins

Betta fish differ from other marine fish because they’re freshwater fish and aren’t used to living in water with salt.

So strange?

It can be a little strange to read that aquarium salt is excellent for treating Betta fish diseases like fin rot and can be added to a freshwater aquarium.

However, both are true; aquarium salt can heal or kill your Betta fish, depending on how much you use during treatment. So, in this article, we’ll explain how aquarium salt can be beneficial for Bettas and how to use it without sending your pet to fish heaven.

What Is Aquarium Salt?

sea salt with shells image

On a chemical level, aquarium salt is identical to regular salt.

Both contain the chemical formula NaCl, which represents the 1:1 ratio of sodium chloride within the salt.

However, what distinguishes the two salts is the presence of additives in table salt. Aquarium salt has none, as it comes straight from evaporated seawater.

Is Aquarium Salt Safe for Use in Betta Fish Tanks?

betta fish with rocks background

Aquarium salt can be safely applied to Betta fish tanks, as long as you don’t apply excessive amounts.

However, it isn’t recommended that you make a routine of adding aquarium salt to your Betta’s water. The fish don’t need aquarium salt to be healthy, and you run the risk of killing your fish.

Moreover, adding aquarium salt to your tank may be a bad idea if your Betta shares the tank with scaleless fish or live plants.

First, due to the drying effects of the salt, scaleless fish like Pictus Catfish will lose the natural protection their slime coat provides against infections and parasites. Snails also fall into this category and won’t fare any better. Actually, they’ll most likely die due to osmosis drying their natural mucus out.

Second, if you add aquarium salt directly to the aquarium water, you could harm live plants with low salinity tolerance.

Third, you risk killing beneficial nitrifying bacteria present in the water—this bacterium help to filtrate the Betta tank by breaking down organic waste naturally. Therefore, losing them equals a less-clean tank, which leaves your environmentally-sensitive Betta susceptible to disease and stress-induced fin rot.

So, we highly recommend placing your Betta in a quarantine tank before medicating it with aquarium salt. Adding aquarium salt to a tank should be a last resort measure if, for whatever reason, quarantining the fish isn’t possible.

Can Marine or Table Salt Be Used as an Alternative?

table salt on a wooden spoon

Using table salt to treat Betta fish diseases is a terrible idea.

Because it contains additives like coloring and flavor enhancers that could prove deadly to fish.

Also, table salt can potentially alter the tank’s pH levels and water quality and doesn’t reload the natural electrolytes in the water.

Betta fish won’t fare any better if you use marine salt. If the name is any indication, marine salt is meant for marine tanks and contains additives that are harmful to freshwater fish. Again, that’s a hard pass for your Betta.

What Betta Diseases Is Aquarium Salt Good For?

betta fish with fin rots

Aquarium salt helps relieve Betta fish diseases like velvet, ich, dropsy, and fin rot. Some Betta keepers restrict the use of aquarium salt for preventative Betta care, while others swear by it as a wonder cure for common Betta fish ailments.

It’s best to think of aquarium salt as a form of first-aid when you don’t have a disease-specific medication at home. So, if symptoms persist after use, resort to proprietary, over-the-counter disease-specific meds.

How Aquarium Salt Works

Aquarium salt dehydrates bacteria and parasites, killing them quickly.

In addition, as the amount of salt in the water increases, these harmful organisms lose water via osmosis.

During osmosis, the liquid travels from a place with a lower salt concentration to another with a high salt level, passing through a permeable membrane during the journey. In this instance, the membrane is the parasite’s skin. So, when the surrounding water has a higher salt level than the parasite’s body, all the fluid within gets sucked out.

Due to how small they are, these organisms are susceptible to suffering from dehydration more quickly than their fishy host and will die from aquarium salt levels tolerable to Bettas.

However, some pathogens aren’t as vulnerable to salt, so it’s a good idea to back up aquarium salt with a chemical treatment.

Other Benefits of Aquarium Salt

Aquarium salt provides the following additional benefits when used directly in a fish tank:

Replenishes Electrolytes

Aquarium salt may help replenish the electrolytes in aquarium water, which are essential for your Betta’s intake of oxygen and expelling CO2 through its gills.

Reduces Nitrites and Nitrates

Adding aquarium salt to your Betta tank reduces the levels of nitrites and nitrates in the water. It may also prevent methemoglobinemia.

Aids Kidney and Gill Function

Aquarium salt aids your Betta’s gill and kidney function. The Betta’s kidneys have the vital role of expelling water from its body, making this a significant benefit.

How to Use Aquarium Salt to Treat Betta Fish Diseases

As already mentioned, aquarium salt is the only type of salt suitable for treating Betta fin rot and other diseases. Therefore, we’ve broken down the aquarium salt treatment into three dosage levels. We recommend you start with the lowest dose.

Ensure you add aquarium salt to the Betta fish tank only during a water change.

Aquarium salt won’t evaporate or be cleared out by the filtration system in the Betta tank. Also, prolonged exposure to salt is harmful to fish and can burn their skin, so adding more salt to a tank that already has a dosage is a sure-fire way to kill your Betta.

Mildest Dose

Add 1 tablespoon of salt for every three gallons of water. Either pour the measurement of salt into the water directly or dissolve it in a small amount of tank water beforehand.

Although this is the mildest dose, it can still effectively treat Betta fin rot and other bacterial and fungal Betta fish diseases.

Additionally, the dose irritates the slime coat on the fish’s skin, making your Betta produce mucus that keeps parasites and microorganisms off the Betta’s body.

Use aquarium salt and let your Betta fish bask in the concentration for four to five days. After that, you can up the dosage level to medium if symptoms persist.

Medium Dose

For a more potent dose of aquarium salt, add a tablespoon of salt for every two gallons of water.

You can treat even more Betta fish diseases and minor fin rot like ich, skin flukes, and fungus using this dosage.

Treatment should last for ten days before moving to the highest dose (if there are no improvements).

Highest Dose

The highest dose of aquarium salt you can add to your Betta tank without harming the freshwater fish is one tablespoon of salt for every gallon of water. Avoid using it in freshwater aquariums that are habitats to scaleless species and plants; else, you risk ending all aquatic life in them.

Aquarium Salt Treatment Duration

When using aquarium salt to treat fish diseases, leave the salt in the aquarium water until the Betta looks healthy again. Afterward, you can remove the salt through partial water changes.

First, replace 30% of the water and observe your Betta for a week. Then, don’t add salt to the newly changed aquarium water. If your Betta’s condition remains stable, repeat the process of changing 30% of the aquarium water without including salt.

If your Betta’s condition takes a turn for the worse, restart the treatment.

Alternatives to Adding Salt to the Whole Tank

Instead of exposing all your aquarium fish and plants to salt, you can isolate the sick Betta and give it a salt bath or salt dip. Let’s briefly explore each alternative in a little more detail:

Salt Bath

Salt baths are a great alternative to filling the tank with aquarium salt because they let you tackle whatever bacterial infections your Betta might have in a shorter timeframe. They’re also great for treating other diseases like swim bladder disease (Epsom salt bath).

How to Do It

You’ll need two large containers, aquarium salt, and tank water.

  1. To start, fill one container with a gallon of aquarium water and add 1 tablespoon of salt.
  2. Next, fill the second container with a gallon of aquarium water and ¼ tablespoon of aquarium salt. You need this second portion of the salt bath to acclimatize the fish before returning it to the fish tank.
  3. Boil the water to 78 degrees Fahrenheit or as close as possible.
  4. After getting the containers ready, transfer the Betta fish from the tank to a plastic bag and float the bag in the first container for a maximum of 15 minutes to adjust the fish to the temperature.
  5. Next, transfer the Betta into the first container and let it swim for eight minutes maximum.
  6. Then, transfer your Betta into the second container.
  7. Finally, transfer the Betta back into the plastic bag and float the bag in the main tank until the temperature equalizes.

Following the above steps prevents your Betta from feeling shocked by the change in environment. Once completed, you can release your Betta into the tank with the other aquarium fish.

Salt Dip

Instead of adding salt to an environment shared by other marine life, you place the fish in a moderately high concentration of aquarium saltwater for a couple of minutes.

Aquarium salt dips are great for killing external parasites.

How to Do It

Add a tablespoon of aquarium salt to two gallons of water and place your Betta in the water for no longer than three minutes. Keep your eyes on the fish the whole time to check for any signs of distress. If the fish appears to be suffering, remove it from the water and return it to its tank.

Frequently Asked Questions

Does aquarium salt help popeye?

It’s debatable whether aquarium salt helps with popeye (a fish disease that makes Betta fish’s eyes bulge out of their sockets). While some people believe it can potentially hinder the healing process, others recommend it as a form of palliative symptom relief.

Unfortunately, we fall in the former camp and would instead treat the Betta fish ailment with a specialized over-the-counter medicine.

Should I use aquarium salt for a new fish under quarantine?

Absolutely! It’s good to subject new fish in quarantine to the aquarium salt treatment before letting them join your existing livestock. Doing so reduces the risk of the new fish passing on any diseases it may have to the others.

Use aquarium salt in the mildest dose described above for two weeks to rid the fish of Betta illnesses. Once finished, you can add it to the Betta tank.

Does aquarium salt affect pH levels in tank water?

You don’t have to worry about aquarium salt affecting the pH levels of the water in your Betta fish tank. When you add aquarium salt to water, the sodium and chloride in the salt become soluble, meaning the oxygen and hydrogen molecules in the tank water won’t be altered.

Are there any plants that can survive in water with aquarium salt?

Yes, there are a few. Examples include plants like Java Moss and Java Fern. However, they’ll only survive if you use a moderate amount of salt, as any higher may prove deadly.


At this point, it should be clear that using aquarium salt for Betta fish has numerous benefits. It’s excellent for remedying bacterial and fungal infections in Betta fish, but it also stimulates the fish’s slime coat, keeping harmful bacteria away.

However, how much aquarium salt you add to your Betta tank is crucial because it can do more harm than good. For example, it may not agree with certain fish that count fresh water as a habitat (scaleless) and fragile plants.

Finally, remember never to use marine or regular salt as alternatives to aquarium salt. While all three are similar at a chemical level, the latter has no additives, being nothing more than evaporated sea water. So, only aquarium salt will do for Betta disease treatment.

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