Aquarium salt: how to use it

Product Recommendations

Our top recommendation is Aquarium Salt by API, which you can buy here on Amazon. We've always used it and not had any issues.

If the API product is out of stock or it doesn't work for you, we also recommend trying Aquarium Salt for Betta Fish by SunGrow, which you can buy from Chewy.

Guidelines for beginners using salt

Aquarium salt can be used as a cure for some betta illnesses. It’s not always a good fit for treating betta disease and sometimes chemical medication is a better choice, but if used properly it can be very effective. For some illnesses, we recommend using both aquarium salt and medication. Either way, here are a few considerations to take into account before you get started, especially if you are inexperienced with salt.

1. Use aquarium salt. This may sound obvious, but it’s worth stating because it will kill your betta if you get it wrong (note: plain sea salt is fine, but if a different culinary salt is used in confusion, it could be fatal for the fish). Aquarium salt is often referred to as just ‘salt’ within the context of treating bettas, and the last thing we want is for a novice keeper to take some table salt and add that to the aquarium. Aquarium salt is specifically and carefully processed for use in aquariums. It’s best to use tonic salt, or any freshwater salt. Any salts other than these could seriously harm your fish. If practiced wrong, salt treatment can do more harm than good. We recommend API’s aquarium salt.

2. Be extra careful if your betta is not the sole inhabitant of the aquarium. Salt can be extremely harmful to other fish and can easily kill aquarium plants. If your betta is in a community aquarium and you wish to treat it, we recommend putting it into a hospital aquarium and dosing with salt.

3. Do research before hand and use it carefully; it’s not a cure for every illness, using it in the wrong situation can do more harm than good.

4. Be sure to measure and use proportion properly. An overdose in salt can also do more bad than good and can seriously harm your fish. Dosage measurements will be stated on the packaging or accompanying documentation. If not, then we give rough measurements in our guides for specific illnesses. Always err on the side of caution and underdose if you are unsure.

5. Remember that salt is not for every illness and its dosage varies between illness, so do your research each time you are treating a disease for the first time or using a particular brand of salt for the first time. Different manufacturers can produce their salt in different ways, adding various mineral salts.

Salt is OK for some freshwater plants

It’s worth noting that some freshwater aquarium plants can be quite tolerant towards salt. Not all plants will be affected by the dosage but it’s good practice assume they will be. If you know all the species of the plants in your aquarium, you can run some research to see if and how they may be affected by aquarium salt. This can be handy if you have a planted betta aquarium and you don’t want to have to create a hospital aquarium specifically for the salt treatment.

Salt is OK for some tankmates

The same can be said for other animals in the aquarium: some are tolerant towards salt, but you need to be certain of this before using it. Certain fish, snails and shrimp can cope with it, others can’t. Bettas are hardy fish and due to their anatomy, they can handle salt pretty well. This can be said for some of the other tank mates that are kept with bettas, but do your research before hand.

If, for example, you intend on using salt to treat ick and your betta is not alone in the aquarium, you’ll need to treat the whole aquarium as ick is highly contagious. If your betta is in a tank with plants and animals that can also cope with salt, great! you can add salt to your aquarium, if not, then you have two options:

1. Medicate the aquarium without salt. This is possible, but may mean that it takes longer to cure the aquarium.

2.Medicate separately. You can medicate your normal aquarium without salt, and transfer the betta (and any other salt-resistant critters) to a hospital aquarium and medicate that with salt. Remember, if the betta is cured first, do not reintroduce it to the ‘home aquarium’ until it has also been cured.

List of illnesses where salt is recommended

As we mentioned, salt can’t be used to cure every illness and it can even have a negative effect in some cases. There are a few illnesses however, where salt can be particularly beneficial.Salt can work well when trying to cure:

We’ve written a short bit about curing these illnesses with salt on the individual illness pages (linked above).

List of illnesses where salt is not recommended

If you’re familiar with any of the above illnesses/diseases, you may know that they only affect the fish externally/affect the fish’s external body. Salt can help heal wounds and kill parasites that don’t like salt water. The same can’t be said for illnesses such as Swim Bladder Disorder, Dropsy and Bacterial Infections as these are all illness that involve an internal ailment (on rare occasions, a bacterial infection can affect the fish’s skin, but seeing as this is a rarity using medicine will be a safer option). Another illness that salt does not help with is Popeye, and in some instances it can hinder the healing process.

Based on the above, here are illnesses that you shouldn’t use salt for:

In summary

The process of using salt as medication should be attempted with care, and only specific proportions should be used. The anatomy of a betta can be different compared to that of other aquarium inhabitants. Salt may help to cure your betta but could seriously harm other animals in the aquarium and even kill live aquarium plants. If in doubt, consider using a hospital aquarium.

‍The same goes for strong or mixed medication: if you are unsure of the effect it will have on the rest of the aquarium, isolate your betta. It’s difficult to know how it may affect other aquarium plants, inhabitants or even the aquarium cycle. The strength and precautions of the medication are usually stated on the product box.

For more information on how to treat specific illnesses, see the rest of our illness section and download our betta illness photo guide.

Using Aquarium Salt To Cure A Sick Betta