Aquarium Salt vs Rock Salt (Differences & How to use)

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by Jason Matthews



There’s something so beautiful and relaxing about an aquarium, right from the slow movement of the tropical fish, the water bubbles, the pretty plants floating away, and even little snails munching on their algae. However, taking care of an aquarium requires a lot of time, and attention as well as using the right products that will not only keep your fish healthy but will balance out the water hardness and keep the tank clean. 

Most people think that salt is just for the human body and for animals. However, this agent can be highly beneficial for cleansing water and absorbing any harmful toxins as well as added moisture. If used in the right manner, salt can also benefit your fish. However, with so many different types of salt on the market, how do you narrow down the best one for you?

Here are some key differences between aquarium salt and rock salt and which one is the right choice for your fish tank. 

Is rock salt the same as aquarium salt?

Aquarium salt

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Aquarium salt is composed of NaCI which is a food preservative and along with other minerals can help to balance out the aquarium water and keep it healthy for fish and other plants. It can also be used as an antimicrobial agent that protects your fish and helps to prevent fin rot, all you need to do is add one tablespoon of this salt per gallon of water and stir well before adding your fish – this ensures that all bacteria in the tank is killed and the pH level is stabilized which can help prevent parasitic diseases and keep your fish happy. 

In addition to this, salt can even disinfect the water. However, keep in mind that this all depends on the type of fish you get as some fish prefer to live in salty environments but some others don’t like the taste of salt. 

Rock salt

rock salt for aquarium

If you’ve heard of rock salt, you must be knowing how effective it is at maintaining the balance of the water, controlling bacteria as well as keeping the aquatic life healthy. This type of salt can also help to stabilize electrolytes in the water and remove any impurities, by adding rock salt to your aquarium you can help:

  • Balance the pH of the water

Rock salt is highly beneficial if you live in areas where the water is hard as it can help adjust the pH of your tank and keep the balance of your water consistent regardless of any fluctuations, temperature, or weather conditions. This salt also contains certain ions that help to not only kill but prevent bacteria from growing in your aquarium.

  • It protects fish and other aquatic life

Adding rock salt to your aquarium can help offer your fish a suitable environment to live in and encourage the growth of good bacteria and algae that can improve the aesthetic of your tank as well as clean up any dirt and debris. However, it’s always advisable to monitor your fish closely and ensure that the salt you are adding is just the right amount as adding too much salt can be harmful to your fish. 

Related article: How to mix saltwater for aquariums

Can I add rock salt to my aquarium?

Adding rock salt to your aquarium can have a range of advantages provided that you add the right amount of salt and monitor your fish closely for the next couple of days. Your first step is to check whether your tank is a freshwater or a saltwater tank, freshwater fish need to continuously remove the salt mainly through urine and breathing so that the water is at a certain balance as compared to saltwater fish. 

Adding rock salt to the water can help:

  • Prevent and reduce nitrate poisoning

The nitrate levels in your fish tank should always be zero or as close to zero as you can get, if not then this can cause a lot of stress for your fish. Adding a certain amount of rock salt to your tank can help your fish stay fine and healthy as well as help to keep your system fresh and consistent. 

  • Kills bacteria and parasites

Certain parasites like flukes, roundworms, and even invasive species can get on the skin and gills of your fish and feed on them leaving your face pale, lifeless, and in some cases dead. A proper amount of rock salt added to your fish tank can help kill any parasitic worms, bacteria, and harmful pathogens that pose a threat to your fish and keep your fish healthy. 

  • It lowers stress

Moving your fish to different locations, taking them out of the water when cleaning the tank, and more can be stressful for your fish. When your fish is stressed, this can weaken its ability to breathe as their gills may not function properly, rock salt contains additional electrolytes that can calm down your fish and help them breathe properly. Adding a certain amount daily can reduce the stress on your fish as well as lower their risk of diseases. 

Can I use Himalayan salt instead of aquarium salt?

himalayan salt for aquarium

When it comes to using Himalayan salt, always pick an ocean-free alternative that has no chemicals and contains antibiotics, natural minerals, and more that can treat your fish and be effective at controlling bacteria and other pathogens. 

This salt can help reduce the osmotic stress caused in tanks and strengthen the gills of the fish as well as disinfect the aquarium which lowers the bacteria in the water. It also contains certain minerals and elements that are essential to maintain healthy and happy fish as well as electrolytes that can accelerate the healing of any injuries and diseases such as tail rot, fungus, and more. 

Related article: Symptoms of too much salt in an aquarium

However, most professionals would not advise adding this salt as it’s not only quite expensive but also not natural for aquarium fish. Investing in rock salt or even aquarium salt will not only be more affordable but it can go a long way at helping balance out the salts in the water as well as offer better gill functionality. 

Can I add aquarium salt directly to the tank?

When purchasing salt, always opt for an all-natural alternative that promotes healthy fill function and reduces stress as well as helps heal wounds. Aquarium salt is the perfect alternative as it helps lower the risk of parasitic infections, promotes your fish’s slime coat as well as can be used for medicated baths and more for infected or sick fish. 

Here are two ways that you can use salt in a freshwater aquarium:

  • A saltwater bath

For a saltwater bath, you can use one teaspoon of salt per gallon of aquarium water and dissolve it in a separate container. Once done, slowly pour it into the aquarium and it should be good for three to four weeks. If you are treating any of the fish then you will need to change your water weekly and slowly reduce the salt so that it doesn’t shock your fish. 

  • A salt dip

If your fish is suffering from a serious infection you will need to perform a dip. For this, you will be required to dissolve five tablespoons of freshwater salt in a container that already contains a gallon of aquarium water. The fish can be placed in this water for a minimum of five minutes; however, it can be extended if the fish isn’t showing any signs of shock or stress. Always do this under the guidance of a professional as if the fish is kept in the water too long it can get injured, affected, or even die. 

Saltwater dips are great at killing any parasites or infections and keeping your fish healthy if done in the right way. Once you place the fish back in the aquarium, dispose of the dip water immediately. 

Don’t Be Salty, Improve the Health of Your Aquatic Life Today!

Most experts will tell you to always start with one tablespoon of salt for five gallons of aquarium water as it’s safe not only for your fish but aquatic plants as well. When introducing a new type of salt to your aquarium always observe your plants and fish for twenty-four hours as well as check on any bacterial, fungal or parasitic infections they are facing. 

Aquarium salt is highly beneficial for your fish. So, when investing in this, always look for a natural alternative that can help your fish maintain their osmosis balance, cure their ailments and lower their stress. Doing your research and picking the right salt for your fish can help you have a happy and healthy aquarium.

Related article: How to Make Tap Water Safe for Saltwater Aquarium 


Jason Matthews

My name is Jason Matthews, and welcome to my website. When other kids were bragging about how their dog could sit and roll over, I was bragging about my latest Betta Fish and the cool sea castle I just added to his aquarium. 

Jason aquariume

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