Can a Goldfish Live in Saltwater?

Can a Goldfish Live in Saltwater?

Goldfish are freshwater fish, and you should never use salt water for the goldfish. These are small fish, and as soon as you put them in saltwater, they will try to move out of this.

Can a Goldfish Live in Saltwater? No goldfish cannot live in saltwater. It is because it lives in a freshwater habitat. Salty water can cause stress, and later death may occur. But if you want to place it in salt water, you have to apply desalination techniques that convert saltwater into freshwater.

Under What Conditions Can a Goldfish Live in Saltwater?

Desalination is a process through which you can convert saltwater into freshwater. Many techniques can low the salinity level.

Most methods are expensive on vast scale processes. They produce maximum waste material, so you have to change it every week. The converting processes may take your time and energy.

Reverse osmosis

You can use a semi-permeable membrane to remove hefty particles of saltwater. Similarly, apply a force to push the high concentration saltwater to a low concentration.

In this way, you can easily extract these ions and molecules, and fresh water is pouring into the aquarium. 

First, you have to supply salt water toward the Reverse Osmosis plant. The machine will take out solid wastes.

It also kills the bacteria present in it. Then apply high pressure to remove the small microorganism. After treatment, environment-friendly water will be available for filling the aquarium. 

Solar still

It is a low cost and old desalination technique. You have to dig a hole in the soil. Place broad plant leaves for producing moisture. You can fix a plastic mug in the center of the hole.

Now cover the hole with a plastic sheet. If sunlight intensity is high, then you will get a pure form of it after two hours. It is enough for stuffing a small container. 


You can mineralize the saline water either at home or chemical laboratory. You have to set the distillation apparatus on the shelf. Pour it into the input tap.

The steam rod will heat it to make it light. The condense coil will cool it, and then it will drop down on the storing tank. Waste will remove in the form of vapor.  

Now take it out from the chamber, and check the salinity level. Its average purifying capacity is 5-10 gallons per day. After every cycle, clean the pot to remove contaminants. You can use Hydrochloric Acid to kill the bacteria; otherwise, they will lay at the bottom of the tank.

Aquatic Plants

Aquatic plants are vital for maintaining the fish habitat. These plants produce oxygen to purify the water and soak up the carbon dioxide.

Water lilies, Golden cannas, and water poppies are the famous aquatic plant known as natural water filters. The plantation also makes the aquarium beautiful and improve their health.  

Capacitive deionization

It is a process in which electrical potential difference removes the charged ions present in it. Two electrodes have opposite charged ions. One electrode will absorb positively charged ion and another electrode absorbs a negatively charged ion.  

You should adjust the system’s freshwater requirements to remove the waste material, such as heavy metal ions. Do not apply pressure to rush the saltwater into a lower salt concentration tank. You can extract these ions from treating the condition to make freshwater.

This method is useful because it changes its hardness. Saltwater contains minerals, for instance, magnesium and calcium, which make it hard. You can improve the performance of the RO plant to give a better result. This project will require a lot of money to neutralize it.  

The capacitive deionization method uses less energy to convert it into soft form. Due to an increase in pollution, heavy ions such as chromium and lead dissolves in saline water. Phosphate and nitrate cause multiple disorders in them.

You can remove these ions using electrochemical techniques. You can get 88% – 90% freshwater by applying this process. 


You have to take five liters of it from the nearby ocean or sea. Boil it until it starts making bubbles on the surface layer. Boiling it will kill the microorganism present in the water. Check its taste after it starts boiling. 

You should not drink it, but you should check the salinity level. Again, heat it to remove more salts. You can observe its smell while inspecting it. Repeating the process will make it purer. 


You can filter the water using filtration techniques such as Cartridge filter, DE filter, and Sand filter. Sand filter and cartridge filter is economical and widely used for purifying it. 

Filtration helps to eliminate the chemical and contaminated particles present in the liquid. It can separate the micro-level germs. It will also prevent calcium buildup in the tank.

Its disinfection is necessary to emit the fungus. The color of the microbial organism is grey or white. The fungus is parasitic and causes bacterial infection in them.

You can add a half tablespoon of salt to it. You will see the change in its color. You can also increase the temperature of water to kill the fungus.  

Why Goldfish can not survive in the saltwater?

There are two types of fish, one that survives in the salt water and the other that cannot live in the presence of excess salt. Goldfish cannot live in such an environment because of their physiological adaptation.

The freshwater fish need less salt to maintain the osmotic pressure in their life. Ocean water contains more salt content compares to others.

So, they discharge a lot of water from their body to regulate the equilibrium. The body organ such as the liver, kidney, and intestine are utilizing to maintain the structure. The role of the kidney is to urinate the waste material and ions. 

Any change in the salinity of water may result in severe stress. It will use a lot of energy to stabilize their body according to the new habitat.

They are sensitive and cannot maintain its structure in saline water. They cannot survive more than five minutes in such an environment. In the end, goldfish will lose its life.

Some other species can survive in both conditions and enjoys a long life. Euryhaline is a species that has such characteristics. 

They have such a body that allows them to handle the worst circumstances. It can adapt its body according to new changes. 

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