If you are ready for a change from freshwater tanks and want to venture further into the wondrous world of fishkeeping without committing to a full marine set-up, a brackish tank is something you should consider. This type of tank is generally easy to maintain since the inhabitants are very adaptable and can handle changes in water pH and salt levels. Do not let this change frighten you; with the right equipment and care, you will have a stunning and successful tank.

So What Exactly does Brackish Mean?

Brackish refers to the water’s salinity, or salt levels, and is essentially the ‘middle ground’ between freshwater and marine water. Naturally occurring brackish water is where fresh streams meet the ocean.

Setting up a Brackish Fish Tank

Any size tank will be suitable for a brackish set-up. Of course, it all depends on what types of fish you wish to keep. There is a range of brackish species that are fit for anything, from nano tanks up to the largest available!  

A brackish tank should have hard water with a pH level between 7.2-8.5, and a specific gravity of 1.005-1.020. Temperatures should be kept between 23-29°C. Make sure to have a heater that will be able to keep these higher temperatures. Your fish will thank you!

Please remember to add the salt mixture and water in a bucket and then add it to the tank. Adding salt directly into the tank can cause serious damage to your fish and plants. Use about 10 grams of marine salt per litre of water.

Filing the tank:

  1. Add fresh water to a bucket- leave space at the top for rising levels from the salt.

  2. Use a heater to make bucket water temperature the same as the tank temperature.

  3. Slowly add the appropriate amount of salt for the amount of water in the bucket.

  4. Stir the salt water.

  5. Let the mixture sit for 20 minutes to ensure all the salt has dissolved.

  6. Stir the water again.

  7. As you add the water into the tank, continuously measure the specific gravity with your hydrometer until you get the right levels.

After a week, the nitrogen cycle will be complete and it is time to introduce your fish to their new home! If you are gradually switching from a freshwater tank, it should first be mentioned that switching water type should happen slowly over a span of weeks. Take out the fresh water (about 20%) and replace it with the salt water mix, increasing the specific gravity levels by .002 per week. This way your fish will not be shocked or harmed form the change.

Products Needed for Brackish Fish Tank Care

It is important to have a thermometer, in addition to a hydrometer or refractometer, in order to measure the temperature and specific gravity of the water. The type of salt used is crucial to maintaining a thriving tank. It is advised that a marine salt mix is used as opposed to an aquarium salt. Also, using table salt is not advised due to silicates and iodide.

It is best to ensure that all equipment used is suitable for both fresh and saltwater tanks. Equipment specified only for fresh water could be damaged by the salt. This can be especially important when it comes to heater and filter choice.

Brackish tanks can use gravel, pebbles, and stone to cover the bottom of the tank. These are common in naturally brackish environments. In order to make your fish feel more at home, purchasing driftwood or tree root ornaments is also a good idea.

Brackish Fish Species Appropriate for Your Aquarium

Brackish fish are used to a naturally changing environment so they will be fine if there are gradual changes in salt levels and pH. Some examples of suitable fish and shrimp are Bumblebee Gobies, Black Mollies 

Maintenance Schedule

When your new aquarium is all set up, make sure you come up with a cleaning schedule! Your fish do not want to live like this…

So to prevent that from happening it is a good idea to change a small amount of water (15%) about once a week. Take out some of the water, use the end of a net to mix around the gravel or pebbles then catch some of the debris that has risen in the net. You should then make a salt water mix (in a separate bucket) using your marine salt. After letting that dissolve, slowly add it to the tank, filling the 15% that you had taken out. Apart from the weekly water change, check your water salinity levels daily because water evaporation will leave salt behind. This will make your aquarium gradually become too salty. It is also strongly advised to give your tank a deep clean about once a month. On top of your normal weekly cleaning procedure, this requires glass and ornament cleaning, and a filter change.

Now that you have the information and guidelines for your new tank set-up, it is time to consider what tank size and fish you would like. Remember the importance of your fish’s needs! Not all brackish fish are the same, make sure they have the right amount of space and that they will be healthy and happy in their lightly-salted environment.

All Pond Solutions is one of the UK’s leading online aquatics retailers, dedicated to bringing home pond and aquarium equipment as well as livestock, to people on a budget without sacrificing quality. Our goal is to provide our customers with goods that are well packaged and delivered quickly and efficiently. If there are any issues we have a spectacular customer service team who has the answers to all queries. 

Don’t forget to leave your comments and questions below. We would love to hear what you have to say about starting and maintaining a brackish aquarium!