What is Brackish Water image

All about Brackish Water – Plants | How to make it?

This article is all about what is brackish water, brackish water plants and how to make this water. Brackish water is the result of mixing two types of water that is, the water which is less salty than seawater and saltier than fresh water. This usually has around 0.5 to 30 grams of salt for every liter which is not a very perfect definition that there can be a wide range of salt concentrations found in brackish water.

What is Brackish Water?

The scientific name for the saltiness of water is salinity. Therefore brackish water can be said to be having a high variance of salinity. The salinity of this water may vary over time. The happening of rain can cause the saltwater and freshwater boundaries to move in turn changing the volume of brackish water during the process. This type of water is generally found in estuaries and in the places where the freshwater river meets the sea. The result of salty seawater and fresh water is brackish water. Some lakes and seas are already brackish.

What is Brackish Water image
What is Brackish Water image

For example, the Caspian Sea consists of brackish water. Salty brackish is often fertile that means fish in this aquatic environment are generally considered as fat and healthy. The organisms that survive in such water usually have some specific adaptation methods in order to cope up with the high concentration of salt. They live in this condition but have to remain adaptable even when changing the salinity of brackish water. The exact definition of brackish water is that it is the “water that is saltier than freshwater and not as salty as sea water”.


Salinity tells about how much salt is dissolved in a liquid and is generally measured in parts per million (ppm) or parts per thousand (ppt). 1 part per thousand means that there is 1 ounce of salt in every 1000 ounces of water. Brackish water has salinity range between 0.5 to 2 parts per thousand of total dissolved salts, seawater has over 2 parts per thousand of dissolved salts and fresh water has less than 0.5 parts per thousand of dissolved salts.


In addition to the factor like salinity, there is another measurement that is density used to differentiate between salt, freshwater, and brackish water. Density tells about how thick your substance is.

  • Density = Mass / volume

For water with a temperature of 77 degrees Fahrenheit, brackish has a density ranging between 997.453 kg/m^3 and 998.584 kg/m^3. Freshwater at 77 degrees with salinity 0 has a density of 997.075 kg/m^3.

Brackish Water plants

Making home brackish water is difficult. When you water the plants at home generally you want to use some pure tap water. This will ensure that water flows into plant cells, making the plants stand straight. Watering the plants with salt water will show the opposite effect. Plants that are living in brackish will have special adaptations to cope up with the salt water. Some of the examples of brackish water plants are:

Smooth Cordgrass

Smooth Cordgrass image
Smooth Cordgrass image

Many estuaries lie on the east coast of the United States where the freshwater rivers and streams of salt water creating brackish water ecosystems. One of the prominent features in these ecosystems is tall grasses which are lining the shore. One of these types of grasses is smooth cordgrass.

Growing anywhere that is from 6 inches to 7 feet tall this plant versatile grass has many adaptations which help it to grow in the brackish water ecosystems. Basically, it has a tough root system that helps it to take hold in sandy soil that is attacked regularly by tides. This helps the grass to stay put in the shoreline that is eroded by tides and current. Smooth cordgrass has the ability to absorb the water from roots just like other plant species, but it also has extra feature to extract fresh water from salt water if necessary.

Black Needle rush

Black Needle rush image
Black Needle rush image

At first look, it seems like it lakes leaves and just simply contains shoots that extend out from the ground. But upon observing it closer you can see that its name black needle rush is apt as it has tiny gray leaves that pointed like needles. This plants growth depends on the salinity of brackish water and makes a home in salt marshes. It grows very tall that is up to 7 feet high in low salinity but with a high concentration of salt restricts its growth to only 1 foot and these are found in Gulf Coast and South Atlantic of United States.

Like the smooth cordgrass, black needle rush also has adaptations which help to survive in salt marshes. The leaves of black needle rush prevent water loss which helps the needle rush to avoid aridity in a salty environment.  It also has adaptations to survive in hypoxic conditions. Needle rush has special tissue named as aerenchyma that acts like straw which transports oxygen from leaves to roots so they are able to make energy. They can even resist the changes in pH that occur in salt marshes.

Mangrove Tree

Mangrove Tree image
Mangrove Tree image

The most ionic of all the brackish plants may be the mangrove tree. Mangrove trees are family of 80 various species lives in coastal intertidal zones. These plants have developed their aerial roots system to cope up with the changing tides where they live. Mangrove trees generally present in tropical and subtropical regions such as South America, the Caribbean, Africa, Florida, Australia, South Pacific Islands, and South East Asia.

How to make brackish water?

Brackish generally refers to the water salinity or the salt levels and is the middle ground between freshwater and marine water. Naturally occurring brackish water is where the fresh streams meet up with the ocean.

Steps for brackish water set-up

Any size of the tank is suitable for this setup. It also depends on what type of fish you prefer to keep. It is always the best thing to keep research on the species you decide to keep prior to purchasing. Pay attention to the specific gravity of their water. Also know about their diet required, size and behavior.

We look at setting a small brackish water aquarium ranging from 6 to 12 gallons without the help of any specialized equipment except the hydrometer for measuring the salt content in water. There are some species that are fit for anything from small tanks to largest available.

A brackish tank should contain hard water with pH level ranging between 7.2 to 8.5 and with a specific gravity of 23 to 29 degree Celsius. Make sure you have heaters to raise the temperature whenever necessary. Add salt and water mixture in a bucket and then into the tank. Adding salt directly to the tank may cause damage to the plants or fishes. It requires about 10 grams of marine salt to water per liter.

Filling the tank

  1. Add fresh water to the bucket and leave some space at the top for raising the salt levels.
  2. With the help of the heater make the temperature of the tank and bucket equal.
  3. Slowly add the salt into the bucket at an appropriate amount of water.
  4. Still the salt water.
  5. Leave the mixture stand for 20 minutes till the salt is dissolved completely.
  6. Then stir the water again
  7. As you keep on adding the water into the tank continuously measure the specific gravity with the help of hydrometer until you reach the right levels.

After a week the nitrogen cycle will complete and now can be ready to introduce fish or any other species to the tank. If you are switching from a freshwater tank then it should be careful that switching water type should be done slowly over a span of a week. Take out the freshwater and add it with salt water mix, increase the specific gravity levels by 0.02 for every week. It is advised to use aquarium salt instead of marine salt mix and table salt due to silicates and iodide. Equipment used should be suitable for freshwater and saltwater tanks. Keep visiting Water Softener Reviews portal for the more useful info.

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