How To Make Brackish Water For Axolotls?

As seen in Are Axolotls Freshwater Or Saltwater Animals?, axolotls come from endorheic lakes. These lakes contain brackish water, which is said to be more saline than freshwater but less saline than saltwater.

Consequently, certain axolotl experts claim that the best type of water for axolotls is in fact brackish water. I’m not an expert, but I’ve successfully kept axolotls in dechlorinated and conditioned tap water – without adding salt. And, from what I know, most axolotl owners do the same.

So, it’s probably safe to assume that you don’t need to make brackish water for your axolotl. However, if you want to make brackish water for your axolotl, then this article may be of help.

In this guide, I will go through the following:

  • What You Need To Make Brackish Water.
  • How To Make Brackish Water.
  • Pros & Cons of Brackish Water for Axolotls.

So, if this sounds interesting to you, let’s jump right in!

NOTE: I’ve personally not tried this method. The information below is based on superficial research, that may be incorrect. There are risks associated with playing around with your axolotl’s water parameters, including illness and death. I recommend seeking professional advice. Proceed at your own risk.

Table of Contents

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What Do You Need to Make Brackish Water?

Items Required To Make Brackish Water

Making brackish water is actually pretty straightforward, if you overlook considerations such as GH (General Hardness), or KH (or Carbonate Hardness) and just focus on salinity itself.

You will need:

  • Large basin or bucket for water.
  • Large bucket or container for salt.
  • Large wooden spoon or stick.
  • Weighing scales.
  • Measuring jug.
  • Salt (see below for the type of salt to use).
  • Dechlorinated water.
  • Water conditioners.

Can I Use Tablesalt To Make Brackish Water?

You can’t simply use standard table salt to make brackish water.

Table salt doesn’t just contain sodium chloride or NaCl, but contains added anti-caking agent.

It may also be iodized; which means that potassium iodide (or another iodine source) is added.

Neither of these additives are required, nor are they good for your axolotl.

Can I Use Marine Salt To Make Brackish Water?

To make brackish water you should use 100% natural marine salt, free of anti-caking agents, iodine, nitrate & phosphate.

This type of salt will be the closest thing to what’s present in the axolotl’s natural habitat.

How Do You Make Brackish Water?

The recipe below assumes that you’re preparing the mixture BEFORE first introducing your axolotl into its tank.

You will also have to cycle your tank properly, as you would with freshwater.

What Salinity Do Axolotls Prefer?

Based on information I found here, axolotls prefer 0% salinity but can tolerate up to 15%.

The calculations below will be based on a 10% concentration in weight, both to make the calculation easier and to err on the conservative side.

Preparing The Brackish Water

Step 1: Dechlorinate Water

As you would do with freshwater, you first need to dechlorinate the water you’re going to be putting in the tank.

You can achieve this by letting it sit out in an open bucket for a day or two. And/or use water conditioner to neutralize chlorine/chloramine.

Step 2: Measure Out Water

Using the measuring jug, fill your empty tank with enough dechlorinated water to fill your tank up to the recommended level.

For example, if you have a 20-gallon/75 litre axolotl tank, measure out 20 gallons/75 litres of water.

Step 3: Calculate Amount of Salt

As I’m going off weight concentration, we need to calculate the weight of 10% of the volume of water you’ve measured out above.

  • We know that 20 gallons (or 75 liters of water) weigh approx. 167 lbs (or 75 kgs).
  • 10% of 167 lbs (or 75 kgs) equals 16.7 lbs or 7.5 kgs.

We now know that we need 7.5 kgs of marine salt.

Step 4: Measure Out Salt

Using the weighing scales, portion out 16.7 lbs or 7.5 kgs of marine salt into a dry container.

Step 5: Mix Salt Into Water

Gently pour the salt into the tank filled with dechlorinated water. Then, using the large wooden spoon or stick, stir the mixture to dissolve the salt into the water.

Step 6: Remove Excess Water

Adding salt into the water will increase the total volume of the liquid inside your tank.

As a result, the water level may be above the recommended mark. You may need to remove some of the water using the measuring jug, until the water level goes back down to the recommended water level mark.

Step 7: Measure Salinity (Optional)

If you have access to a salinity meter, such as a hydrometer, then follow the instructions provided with it to confirm that the salinity level is as desired (in this example it would be 10%).

Pros & Cons of Brackish Water

There are many pros and cons of making brackish water for your axolotl. I’ve listed out the main ones below.


  • Closest water type to the axolotl’s natural habitat.
  • Can help prevent/slow down certain infections, such as fungal growth.
  • Will help you take your axolotl expertise to the next level.


  • Brackish water can be complicated to make (not beginner friendly).
  • Brackish water may not be suitable for other potential tank mates.
  • Salinity may interrupt the growth of established beneficial bacteria.
  • Adds an extra cost to the total cost of axolotl ownership.
  • Dangerous, risk of illness or death if something goes wrong.

For the reasons above, I don’t recommend making brackish water for beginner axolotl keepers.


Hello and welcome to Pets From Afar. I'm Glen. My daughter Siri and I are mad about axolotls. I created this website to document our findings and experiences, as we learn more about these amazing amphibians. Follow along and enjoy the fun!

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