How to Make Aquarium Salt at Home + 5 Substitutes

Despite what many tank owners think, salt isn’t reserved to saltwater aquariums only. Many people learn how to make aquarium salt at home so they can use its benefits.

Aquarium salt is pure sodium chloride. It is not the same as salt used for saltwater tanks. Adding this particular salt to the aquarium can be extremely helpful to freshwater fish, especially if they’re battling certain diseases, such as fish itch.

While it is rather good for your fish, many people refuse to buy it due to its high price. 

Fortunately, there are several substitutes to aquarium salt that you can use instead. If anything else, you can learn to make it on your own!

Here’s how to make aquarium salt at home and what substitutes you can use!

How to Make Aquarium Salt at Home

Fortunately, there is a way to make pure sodium chloride at home – but it isn’t easy. In fact, it is so challenging and requires such components that you might be better off buying some of the substitutes we’ve listed below. 

Still, if you feel like you’re up to the challenge, there is a recipe found in Chemical Oceanography by Frank Millero. I’ll explain it as plainly as possible.

But first, here’s what you’ll need:

• 23.98 g sodium chloride
• 5.029 g magnesium chloride
• 4.01 g sodium sulfate
• 1.14 g calcium chloride
• 0.699 g potassium chloride
• 0.172 g sodium bicarbonate
• 0.100 g potassium bromide
• 0.0254 g boric acid
• 0.0143 g strontium chloride
• 0.0029 g sodium fluoride
• Water to 1 kg total weight.

While this sounds like a huge chemical experiment, the truth is you can find most of these components at a local chemical store. Also, most of the ingredients are fairly cheap. 

However, some, such as strontium chloride, are rather expensive. Unless you happen to have some lying around, you might be better off buying regular aquarium salt – at least when it comes to finances..

Can I Put Table Salt in My Fish Tank? 

As I’ve already mentioned, aquarium salt is nothing but sodium chloride. Yes, it has the same chemical compounds as table salt, but it is pure, without additives and toxins. This makes it safe for freshwater fish.

In other words, table salt is not the best choice for your fish. It is iodized, although in minimal amounts. Still, this is enough to cause issues to the more sensitive water creatures.

What Can I Use Instead of Aquarium Salt?

Just because you shouldn’t use regular table salt doesn’t mean there aren’t some good substitutes. 

For example, you might use:

• Epsom salt,
• Kosher salt,
• Rock salt,
• Canning salt, and
• Pure, non-iodized kitchen salt.

While these salts aren’t pure sodium chloride, they’re not iodized and they don’t contain harmful chemicals. This makes them perfectly safe for your fish. 

Even if they contain a component called sodium ferrocyanide, don’t panic. Many salts contain this anti-caking agent in trace amounts. It is so minimal it won’t harm even the most sensitive fish, shrimp, or any other tank inhabitant!

How Much Epsom Salt Do I Put in My Fish Tank?

Out of all these substitutes, Epsom Salt is likely the one most people will choose. This is because it is easy to find, fairly affordable, and you can hardly go wrong with it.

Epsom salt is a mixture of sulfate, magnesium, and oxygen. All of these ingredients are perfectly safe for your fish. Also, they come in just the right amount to be beneficial without any harmful effects – as long as you use the proper dosage. 

As for the proper dosage, this will depend on the condition you want to treat. While some people would say that using a teaspoon per gallon of water is the universal dosage, from my experience this can be too much for certain fish. 

In general, here’s the amount of salt depending on the disease:

• For treating fish constipation, use a teaspoon per gallon of water.
• For dropsy, use ⅛ of teaspoon per 5 gallons of water.
• For swim bladder disorder, use the same amount as for dropsy, but increase the water temperature to 78 – 80 degrees.

Other Uses of Epsom Salt

Another reason why many people use epsom salt instead of standard aquarium salt is as it can increase water hardness.

While it’s true that most of the time you’ll want to keep your water soft, you don’t want it to be too soft. Also, some fish, such as chromides, guppies, and cichlid glass fish prefer their water to be a bit on the harder side. This is where Epsom Salt becomes handy.

According to the Aquatic Community, if you add just 1 milliliter of Epsom Salt to a 2.6 gallon tank, you’ll increase the water hardness by approximately 70 mg/L CaCO3.

Of course, it’s essential to note that you shouldn’t make sudden changes to your tank. Most fish and shrimp species, especially caridina shrimp such as the blue bolt shrimp are very sensitive to unstable water parameters.

Bottom Line

Now you know how to make aquarium salt at home. However, this might not be as easy as you might’ve thought – although it is possible.

Whether you have some of these components at home or you feel like you’re ready for a challenge, you might want to attempt this on your own. 

One word of advice, though: Never test homemade aquarium salt in a tank with living fish. Instead, try adding a bit of it to the water and test the parameters using a testing kit. 

This will give you an idea of whether you’ve made it the right way without endangering the tank’s inhabitants. 

Still, you might be better off using some of the substitutes I’ve listed. They’re mostly cheap, easy to find, and you can hardly go wrong with them. Just remember to carefully read the ingredients beforehand!