Axolotl Water Requirements: A Complete Guide

Setting up good water parameters in your tank is crucial for a healthy axolotl. Axolotls have specific water requirements and if those requirements are not met, the water can harm or kill your axolotl.

In this guide I’ll go through all of the important water requirements for your axolotl such as pH levels, temperature, filtering, and more.

If you’re new to keeping an axolotl, I’ll explain each of these requirements in detail.

At the end of this guide I’ll provide a handy summary of all the water parameters needed to keep a healthy axolotl.

pH Requirements: What pH Means For Your Axolotl

pH is how we measure the level of acidity or alkalinity of our water. Getting your tank’s pH to the right levels is important for a healthy axolotl.

Axolotls require a pH of 6.5 to 8.0 with the optimal level around 7.4 – 7.6. Keeping your water within this range is crucial for your axolotl’s health.

If the pH moves outside of the 6.5 to 8.0 range, you will start to experience issues with ammonia toxicity.

Let’s look at how pH works, how to test it, and how to adjust it so you can confidently keep your tank in the ideal range.

What is pH?

pH is a scale that measures the acidity or basicity (alkalinity) of a solution. Typical values in the scale are from 0 to 14 (higher than 14 is possible).

A pH of 7 is considered ‘neutral’ that is neither acidic or basic. Pure water has a pH of 7. Typical tap water can have a pH anywhere between 6 and 8, depending on how your water is treated.

pH values less than 7 are acidic and values greater than 7 are basic. As an example, lemon juice has a pH of around 2 (very acidic) and baking soda has a pH of 9.5 (basic).

Depending on the pH of your tap water, you may find that your pH level is ideal for axolotls (around 7.3 – 7.5).

Why is pH so important?

It is crucial that you keep your tank water’s pH level within the range shown above. If the pH level moves outside of this range, it can potentially kill your axolotl.

pH is important because it affects the toxicity of ammonia. When pH becomes greater than 8.0, ammonia becomes incredibly toxic and can poison your axolotl.

Keeping pH within the safe range limits ammonia’s toxicity.

If you don’t know about ammonia, it’s covered later in this guide.

Testing your water’s pH

Regular testing of your tank water’s pH is important as your axolotl needs a stable pH level.

You can test your pH with a pH kit like the one shown below:

Axolotl Water Testing Kit

Aquarium test kits like the above are a must-have for every axolotl owner.

Testing pH is as simple as filling the vial to the marked level, then adding the correct number of test solution drops into the vial.

Give the vial a shake (with the cap on) and compare the solution’s color against the chart.

Most kits will give you two different tests for pH: a pH test and a ‘high range’ pH test. These kits give you a more accurate reading than a ‘wide range’ pH test.

Adjusting your pH

You’re able to raise or lower your pH using two different additives called ‘pH Up’ and ‘pH Down’. As you might expect, these additives move the pH up or down.

Let’s say you test your pH and it shows 8.2, that level can be hazardous to an axolotl so it needs to be adjusted. We want to lower the pH to around 7.5 (ideally), so we need to use pH Down.

It’s important to make small changes to pH. You don’t want the pH level to swing too quickly or it could cause problems.

Make a small adjustment to pH, let the water settle, then measure the level. Repeat this until you end up at the right level. Be patient as you don’t want to stress your axolotl out.

Temperature Requirements For Your Axolotl

Axolotls are very sensitive to water temperature and the wrong level can stress them out and cause issues such as fungal infections and potentially death.

Axolotls need tank water at a temperature between 15 and 23 degrees Celcius (59 – 73 Fahrenheit). The optimal temperature is between 16 and 18 degrees Celcius (60 – 64 Fahrenheit).

Water temperature can affect behavior and appetite, so let’s look at what happens if the water temperature is outside of safe levels.

Axolotls in warm water

If the water temperature is above 24C (75F), it can cause serious stress to your axolotl. High temperatures increase metabolism, which means your axolotl will burn through a lot of energy.

An increase in metabolism means your axolotl will have an increased appetite.

If the high temperature continues, the stress can lead to disease such as fungal infection. This can quickly lead to death if not dealt with.

A high water temperature can also cause ammonia levels to rise, which can quickly become toxic to your axolotl. Keeping water temperature below 24C (75F) is crucial.

How to cool your tank water

If your water temperature is normally fine but you’re experiencing a heat-wave, you can reduce the temperature by freezing bottles of water and placing them in the tank.

Keep the bottle sealed and let the ice thaw out. This will cool the tank water without introducing chlorine into your tank. When the bottle completely thaws out, place it back into the freezer to refreeze.

If you have a large tank, or your tank’s water temperature is likely to rise above 24C (75F) regularly during summer, consider buying a cooling system for your tank.

Axolotls in cold water

While axolotls struggle in warm water, they’re more resilient with colder water. You still want to aim for the ideal water temperature range, but colder than ideal water won’t quickly become a problem.

When the water temperature falls below 16C (60F), your axolotl’s metabolism will decrease. This leads to a loss in appetite and slugglish behavior.

As axolotls do not hibernate, the cold water could eventually become an issue and cause sickness.

If your tank is in an area where it may experience cold temperatures, consider adding a heater to keep the temperature at the ideal level.

Ammonia Levels in Your Tank

Ammonia in your tank can quickly become a life-threatening problem for your axolotl. Understanding how ammonia enters your tank and how to deal with it is crucial to the health of your axolotl.

Let’s look at the different ways ammonia can enter your tank water.

Ammonia in tap water

While tap water doesn’t contain ammonia, adding untreated tap water to your tank could increase the levels of ammonia if your local water company uses chloramine.

Chloramine is chlorine bonded to ammonia. It’s a more stable compound than chlorine, so even if your water isn’t currently using chloramine, it may in the future. A lot of water companies are switching from using chlorine to chloramine.

Fortunately, it’s quite easy to treat any tap water before you add it to your tank. Tap water conditioners and water agers deal with the chlorine or chloramine in tap water.

You may have heard to leave your tap water in a bucket overnight before adding it to your tank. This is an effective way of evaporating chlorine, but it won’t deal with chloramine. Use a water ager or conditioner to treat for chloramine.

Ammonia in decomposing organic matter

When organic matter decomposes, it leads to higher levels of ammonia. Uneaten food, excrement, and plants are the main sources of ammonia.

If your axolotl doesn’t eat all the food you put into the tank, you need to remove the excess food before it starts to decompose.

This is why having too many axolotls in the one tank can cause issues. More axolotls create more excrement, which leads to more ammonia.

Testing for Ammonia

If the ammonia level in your tank rises above 1 ppm (part per million), it can become life-threatening to your axolotl.

A standard test kit provides a quick and easy way to test for ammonia.

Test your tank weekly for an established tank, or daily for a new tank. A new tank’s ammonia levels can potentially spike in a short time, so you want to stay on top of it.

Treating Ammonia in your tank

If you detect ammonia in your tank, there are a few ways you can treat it.

As mentioned earlier, your tank’s pH level affects the toxicity of ammonia. A pH above 8.0 increases the toxicity of ammonia. Lowering the pH using ‘pH Down’ is a quick way to stop ammonia from becoming life-threatening.

You can also change some of the water to reduce the overall level of ammonia. Replacing water removes some ammonia and it may also reduce the pH at the same time.

When you detect high ammonia levels, avoid adding more food into the tank until you completely remove ammonia. You don’t want the extra food or excrement to add more ammonia.

Preventing Ammonia

A new aquarium is far more likely to experience ammonia issues than a well-established aquarium. If you have a new tank and are thinking of getting an axolotl, you need to do a complete cycle of your tank first.

Remove any uneaten food and waste as soon as you see it in your tank.

Nitrite and Nitrate Levels in Your Tank

It’s important to understand what nitrite and nitrate are because they play an important role in your aquarium’s filtration system.

What is Nitrite?

Nitrite is produced when bacteria in your tank consumes ammonia. You may have heard of ‘nitrifying bacteria’. They do exactly what it sounds like – they create nitrite.

As mentioned earlier, ammonia can quickly become toxic to your axolotl. So nitrite is good, right?

Unfortunately, converting ammonia to nitrite isn’t enough to keep your axolotl healthy. Nitrite is harmful to axolotls. It isn’t as toxic as ammonia, but it is harmful.

The ideal level of nitrite in your tank is zero. Healthy aquariums will always have a nitrite level of zero (or close to zero). If your tank has a high nitrite level, you need to quickly deal with it as covered below.

What is Nitrate?

The final step in the filtration process is for bacteria in your tank to convert nitrite into nitrate. While nitrite is harmful to axolotls, nitrate is relatively safe.

Low levels of nitrate are fine for your axolotl. If you regularly maintain your tank with water changes, your nitrate levels should never become a problem.

When nitrate levels become too high, it can become toxic to your axolotl. High nitrate levels can also cause an algae bloom.

The ideal range of nitrate in your tank is between 20 and 60 ppm (parts per million).

When the level of nitrate rises above 60-80 ppm, it can cause issues and start an algae bloom.

Detecting some nitrate in your tank is a sign of a healthy biological system. Detecting nitrate means there is bacteria in your tank converting ammonia to nitrite, then nitrite to nitrate.

If you don’t detect nitrate in your tank, it may be a sign something is wrong.

Testing for Nitrite and Nitrate

A standard aquarium test kit (as covered above) should contain tests for nitrite and nitrate.

You should aim to check nitrite levels as often as you check ammonia levels, as both are toxic to your axolotl.

You don’t need to check nitrate levels as often, but it’s a good idea to check them at a regular interval to make sure you’re keeping the biological filtration system running properly.

Water Hardness

Water hardness is the measure of how much dissolved calcium and magnesium salts are in the water. “Hard” water has a high concentration of dissolved salts, while “Soft” water has a low concentration.

There’s often confusion as soon as the word ‘salt’ is brought up when talking about water hardness. You might see forum posts where people say “don’t add salt to the water, axolotls require freshwater!” while other people say salt is important for a range of reasons.

What is salt?

What we commonly think of as “table” salt, Sodium-Chloride, is only one type of salt. Without getting into the chemistry, it’s important to know that there are other types of salts. Epsom salt (Magnesium sulphate) and baking soda (Sodium bicarbonate) are two examples of salts.

When we talk about water hardness, we’re talking about the range of different salts that may be present in water.

Axolotls prefer slightly hard water, which means they prefer water that has a good concentration of dissolved salts.

Depending on your tap water, you may already have enough dissolved salts to satisfy your axolotl. If your water is soft, then adding salts (not table salt!) to your water is a good idea.

Why Salts Are Important to Your Axolotl

It’s easier to think of salts as minerals. We need minerals in our diets and know the benefits of including magnesium and calcium in our diet. It’s the same with axolotls.

Minerals from dissolved salts can contribute to gill function, slime coating, and other health benefits.

How to Increase Water Hardness

If your tap water is soft (you can check with your local water company), adding salts is important to keep your axolotl healthy. If your water is already hard, there’s no need to add anything extra to your water.

You can’t just add table salt to your tank as that’s only one of many different types of salts. Instead, there are solutions available that contain a range of different salts at different levels.

Holtrefeter’s Solution is the most popular and it contains a balanced solution of salts.