Tweet

Pocket

I get quite many questions about what does salt bath do to your fish as well as what aquarium salt really is for.

So I will try to explain it with goldfish as an example.

Effect of aquarium salt

Do you know salt bath?

Have you ever heard of it?

If you are in an aquarium hobby, you may come across with this term “salt bath” or simply adding salt into freshwater aquarium. It is the technique you may seek especially when your fish is not in a good health.

Salt bath

The salt bath is used not only to goldfish but can be effective to any other fish such as fighting fish to recover its physical strength and/or from sickness or disease. This technique has been used for quite long time alternative to using aquarium medicine.

But why can fish be recovered by introducing into salt bath?

Let’s talk more in depth about it.

Reason to use aquarium salt

There are reasons for using aquarium salt or salt bath in order to cure sick fish and/or to recover its physical strength.

Osmotic Pressure

When considering the effectiveness of salt bath, you should know about “Osmotic Pressure”.

So, the water is forced to flow from lower concentration part to higher concentration part.

In general speaking, freshwater fish do not drink water.

Hence, they have drainage ability in order to live in that environment.

They are always spending some energy for draining water from their body but when they are sick, it is obvious that it functions in poor performance. So they require more energy to solve that issue and because they’re spending more energy to cover that, they cannot afford further energy to use to fight back for its sickness.

So what do you do?

This is where aquarium salt comes in. You can slightly increase the salinity so that the osmotic pressure balances out. Meaning, fish does not require extra energy to cope with it so they can spend it towards recovering.

Blood salinity for goldfish is said to be somewhere around 0.9%. And this can decreases down to somewhere around 0.45% when they’re ill. You may see them gasping for air or it may affects to vision and hearing causing abnormal behaviour around that level.

Some people say using aquarium salt to make up to 0.5% salinity would work as a tonic. This amount is ok, when goldfish is healthy and active.

However, when they’re sick and as mentioned above, if the blood salinity is around 0.45%, increasing the salinity to 0.5% is definitely “NO”.

Remember the definition of osmotic pressure. Water is forced to flow from lower concentration to higher concentration.

You would like to help the fish recover by adding aquarium salt but 0.5% salinity can change the water flow direction that can be lethal.

Hence, I always recommend using aquarium salt to the water up to 0.3%.

That is 3g per litre.

Bactericidal effect

Salt bath is not the ultimate solution for all diseases but there is important reason to use it. That is its chemical reaction on parasites.

Most freshwater parasites are simple creatures and only adapted to dwell on their host fish, hence, freshwater. When you add aquarium salt to increase salinity for treatment tank, these parasites simply cannot deal with that osmotic pressure and are killed by rapid dehydration.

Recover slime coat

As said in above section, adding aquarium salt up to 0.3% helps to recover its physical strength and killing parasites by dehydration.

Since fish become better, its metabolism functions properly which leads to recovering injury and/or reproduce its slime. When you can help them reproduce slime, the resistance to parasites increases and thus goldfish can be more capable of protecting themselves.

Not ultimate solution

Again, salt bath is not for all purposes. This method generally works effectively against external parasites. Good enough benefits though when you consider how safe and easy to get hold of.

Also, such low treatment levels will not harm the biological filter as long as you do not over-dose it.

Which aquarium salt to use

In case you’re in need of aquarium salt to treat your fish, NEVER USE TABLE SALT THAT CONTAINS ADDITIVES. Those additives and spices in table salt can be lethal to your fish so absolutely “NO”.

So which salt can you use?

Freshwater aquarium salt

This product is particularly made for aquarium use which is created from sea water and doesn’t contain harmful additives. You can purchase it from pretty much any pet shop that sells aquarium fish and accessories.

Non-iodized rock salt

This is made up of sodium chloride and it doesn’t contain iodine and calcium silicate. Additives and extra ingredients are just bad for your fish so avoid anything include those.

Feeding during treatment

Basically, you do not feed while you’re treating fish.

You may decide to do a salt bath on other tank where you don’t have enough bacteria grown.

When you commence salt bathing to your fish, typically they are unwell so they won’t appreciate it.

You must keep the water quality on top notch especially while you’re treating fish so minimize the risk that causes water to deteriorate.

Conclusion

The salt bath has been used in the aquarium industry for quite long time. You only need to commence salt bathing when you can afford to quarantine new fish and when you notice fish is not well.

As long as this method is done properly, you will increase the possibility that your fish can recover and/or prevent diseases.