Can Aquarium Salt Go Bad? (Yes, Here’s How To Prevent It)

Aquarium salt is an essential part of having a saltwater aquarium. It’s literally impossible to have a saltwater aquarium without having some aquarium salt. But this raises an interesting question, does aquarium salt go bad?

The short answer is that aquarium salt does not go bad. It won’t expire like food. However, aquarium salt will absorb moisture from the air, which can cause the salt to clump together. The salt clumping together can attract bacteria and dirt to the salt.

This can cause it to go bad.

The short answer is that aquarium salt itself won’t go bad, but it can create a situation that leads to the salt becoming unusable. This is why it’s imperative to properly store aquarium salt.

We will cover this in more detail in the rest of the article.

The Difference Between Aquarium Salt and Regular Salt

Aquarium salt and the salt that you have on your table some differences. The biggest one is that table salt typically has additives to the salt like iodine. These additives are perfectly safe for humans, but they can be extremely problematic for fish and aquatic plants.

Aquarium salt, on the other hand, does not have any additives. It’s 100% sodium chloride, which is perfectly safe for most fish in small doses.

Anyway, it’s ill advised to add table salt to a fish tank.

Here’s Why You Should Use Aquarium Salt in Your Fish Tank

Aquarium salt can greatly benefit your fish tank. You might think this does not apply if you have a freshwater fish tank.

No, you can still use aquarium salt in a freshwater tank. Most freshwater fish can handle small amounts of salt in the tank. Some fish, like African cichlids, need a small amount of aquarium salt in order to live optimally.

That’s great because aquarium salt has the following benefits:

  • Aquarium salt kills a lot of bacteria and parasites.
  • It can improve the color of your fish.
  • The slime on your fish will improve from adding aquarium salt to your tank.
  • It can make the medicine used to treat illnesses in fish more effective. Remember, aquarium salt is an anti-bacterial and anti-parasitical.

Now, aquarium salt does have some drawbacks and you should not just add it to your fish tank without doing proper research. Here are some things you should consider before adding aquarium salt to your fish tank:

  • Even small amounts of aquarium salt can kill aquatic plants. I strongly recommend not adding aquarium salt to your tank if you have freshwater plants in it.
  • Certain types of fish are sensitive to aquarium salt. This includes fish that do not have scales and most bottom feeders.
  • Aquarium salt does not evaporate. This means you should not keep adding it to your tank unless you are removing the water from the tank (ie. water change).

How to Prevent Aquarium Salt from Going Bad

As mentioned earlier, aquarium salt does not go bad per se. But it will clump together after enough time because salt absorbs moisture from the atmosphere. Here are some ways you can make your aquarium salt last just a little bit longer:

  • Store it in a cool, dry place.
  • Store aquarium salt in an airtight container.

Some people like to add rice to their salt because the rice will absorb the moisture rather than the salt. However, I do not like to do this with aquarium salt as the rice can add more contaminants to the salt.

Now, if your aquarium salt has already begun to clump, then there’s no need to fear. It’s still usable despite the clumpiness. It’s just a little harder to work with when it clumps together.

My recommendation is to dissolve the salt in a glass of aquarium water and then add it to the tank. Obviously, if the salt has mold or mildew on it, then you will have to throw it away. You don’t want to add mildewy or moldy aquarium salt to your fish tank.

Final Thoughts

Well, that covers it for whether or not aquarium salt can go bad. It can’t technically go bad because it’s salt, but salt does absorb moisture over time. This makes it a little more difficult to work with and can even attract mold and mildew.

Storing your aquarium salt in an airtight container and in a cool, dry area should extend the life of it by a little bit.

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