How to Setup Brackish Water Tank For Guppies?

So What Exactly does Brackish Mean?

Brackish refers to the salinity of water, or in other words salt levels in the water, it is the middleware between freshwater and marine water.

Natural occurring brackish water is found where fresh streams and oceans meet.

Brackish Water = Part Fresh Water + Part Salt Water

Guppies and Brackish Water

Is Brackish Water Safe For Guppies? The simple answer is both Yes and No; it depends on the type and breed of guppies.

Guppies do fine in brackish water until the seawater is at half its strength,

A pure breed of Guppies usually stress out and die anything above half strength saline level,

But we can acclimate feeder and wild guppies under some care to full-strength seawater.

How To Set Up Your Brackish Aquarium Step By Step

When you are first setting up your guppy aquarium most likely to go with the standard freshwater setup.

Some guppy enthusiasts even create an environment more like the natural habitat that the guppy breed was originally used to.

While it may sound a little overwhelming it really is not that difficult as the brackish water is comprised of part freshwater and part saltwater.

The reason that some individuals go this route is that the natural habitat of the guppies was in the swamps and the water in these areas was considered brackish.

Brackish Water for guppies
Is Brackish Water Safe For Guppies?

Beginners guide for setting up a brackish tank.

It takes a little bit of work to set up the tank and to maintain it but many find it well worth it.

You will have to start by finding the proper aquarium that will allow for the addition of saltwater.

Glass and acrylic aquariums do work well with this but you want to stay away from any tanks that have metal frames or thermometers, or anything that could be affected by the salt.

You will also need to have a hydrometer that allows you to measure the gravity that will be in your tank.

Even though you are doing a brackish set up you still have to be cautious of the tap water that you are going to be adding to the tank.

Many times tap water has chlorine treatment and for that reason, retreating is a must.

Make sure that you condition the water that you’re going to be putting into the tank before you add any salt.

For Further Reading

How do you make salt brackish water?

The type of salt that you are going to be using is special salt or Marine Salt.

You do not want to use freshwater aquarium salt or your regular table salt for this setup.

You should be able to find that you have a selection of Marine Salt at your local fish supplier.

Once you have the right salt you can look at the directions that are on the package,

and you will need to stir the water until the salt has fully dissolved.

This can take a while as it depends on the amount of water you are going to treat with the salt and its temperature.

For a brackish water fish tank, gravity is going to be really important as this makes sure that you’ve added the right amount of salt.

The density of brackish water?

The density of brackish water usually ranges between 1.003 to 1.010.

For this purpose, we are going to need the hydrometer to give us precision reading.

Guppies are most happy with brackish that is close to the lower end of these figures.

The pH of the brackish water for guppies?

Guppies are happiest and healthy when they are in the range of 7 to 7.6 pH

You will also want to know what the pH of the water is and guppies can live in?

Well, to be precise water in the ranges of pH between 6.8 to 7.6 is absolutely

One thing that you have to keep in mind about setting up your brackish tank is that not all fish will be able to tolerate this type of water setup.


So you’ve got to plan for the future as to what you’re going to be adding to this tank.

Also, remember that you don’t want anything around the tank that is metallic in nature.

Sea Salt is the major cause of corrosion and fast decay of metals such as copper and Iron.

If you are switching a freshwater tank over to a brackish one tank do this slowly in stages.

Start by replacing approx 0.25% of the tank water weekly until you’ve reached the gravity point as mentioned.

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