Guide on Axolotl Tank Setup, Water Parameters and Nitrogen Cycle

Axolotl Tank Setup – Nitrogen Cycle and Water Parameters

Axolotls are very sensitive to water quality and chemistry, so you must make sure all water parameters are ideal for your pet before introducing it into the tank. In this post, you will learn how to cycle the tank, mature it, how to check water quality and use filtration.

Before you introduce your axolotl into a new tank, you must cycle (nitrogen cycle) or mature water in your aquarium and test water parameters. It’s important for the health of your axolotl that parameters are ideal.

Cycling an axolotl tank step-by-step

  1. Getting a tank and filling it with dechlorinated water – if using tap water, add aquarium water conditioner like this to remove chlorine and chloramines in it. However, never use distilled water.
  2. Run the filter with biological media (at all times) and set up the tank.
  3. Add kick start nitrifying bacteria to start the cycling process
  4. Introduce ammonia to feed bacteria.
  5. Test water parameters (pH, KH, nitrites, nitrates, hardness or GH) using a test kit like this one.
  6. Allow around 10-14 days for cycling to complete.
  7. Once nitrogen cycle is complete, introduce your axolotl.
  8. Do water changes, change about 20-30% water weekly.
  9. Test water parameters weekly for first 5-6 weeks, and then once in 2 weeks after that.

You will find more information on each step below.

What does maturing or cycling (nitrogen cycle) your axolotl’s tank mean?

Axolotl Water Cycle, Nitrogen Cycle and Water Parameters - Full Guide

Axolotl’s poop, uneaten food and dead plants will produce ammonia, which is toxic to your axolotl. Ammonia is then turned into nitrite (NO2), and then nitrate (NO3) to make it less toxic. Then, water changes once a week will ensure that the levels or nitrates are kept low.

When you add water into a new aquarium, it is not yet ready for you to introduce an axolotl into it. That’s because it is lacking a set of essential bacteria that will help break down your axolotl’s waste and turn it into a less toxic waste.

Axolotls produce quite a lot of waste, and they are messy. That’s why chemical composition of water and parameters are important for you to keep a track of and test regularly. Otherwise, toxic ions will make your axolotl sick very quickly.

Summary: Ammonia from waste – nitrite – nitrate. Ammonia is toxic, so nitrifying bacteria in this nitrogen cycle convert it to final product nitrate, which you then remove with weekly water changes.

Make sure to perform weekly water changes of 10-30% water, using an aquarium water changer like this one.

Axolotl tank nitrogen cycle step-by-step

Step 1: Adding dechlorinated water

Tap water that you will use for your axolotl’s tank contains chloramines and chlorine, which is toxic to aquatic life.

Before you fill the aquarium with water, please neutralize tap water by using an aquarium water conditioner like this. Follow instructions on the bottle to make sure you add just enough of a water conditioner.

However, never use distilled water. Stick to tap water (easiest), but make sure to condition it every time before adding to an aquarium/when making water changes. Fill the tank to the top, but allow 2 inches (5 cm) between the tank and the lid.

Make sure your tank’s filter is already running and that you have set up thermometers in your aquarium as well. That’s because most nitrifying bacteria will end in a filter.

Step 2: Adding a cycling kick-start bacteria

To start cycling your tank (nitrogen cycle), you need to kick start the cycle. This is not possible without nitrifying bacteria, that are essential in this cycle.

To speed up process of water maturation/cycling, you can add kick-start freshwater nitrifying bacteria. To do this, you can add some kick start cycling nitrifying bacteria for freshwater tank like this.

If you don’t wish to get an aquarium kick start solution, you can also add some water from an established tank.

Or, even better, you can remove media from the filter (such as sponge from a sponge filter) in an established tank, and put it in your axolotl’s filter. This filter media will have bacteria, that will kick-start the whole nitrogen cycle.

This step is the main one, to start maturing tank water, and can take from 7 days to 2-3 weeks. Please be patient, as it’s very important.

Step 3: Adding ammonia to feed bacteria

To start the nitrogen cycle, you will need ammonia in the tank that will be later consumed by bacteria and turned into nitrite and then nitrate. There are few options on introducing ammonia in a tank.

The best option is to add some household/bottled ammonia if you have it at home. This will be pure ammonia, and will be easy to monitor. It will also speed up the process significantly.

You would need to add just a little for ammonia levels to rise to around 2-4 ppm. This will be around 0.5-1 tablespoon per gallon of aquarium water.

However, if you can’t get any pure ammonia, you can put some fish flakes/food pellets in water and let them decompose. This will take much longer and might not be as accurate however.

Use a test kit mentioned above or test strips like this to check for ammonia levels in the tank water.

Step 4: Keep testing water to see if cycling is complete

After this, start testing water for various parameters daily to see if it’s ready for an axolotl. To test the water, you will need a test kit or test stripes (often to test for 5-6 parameters).

You will have to test water for pH, KH, GH (water hardness), ammonia, nitrite, nitrates. Nitrate levels must be less than 40ppm for it to be ready for an axolotl introduction. Make sure to reach ideal parameters:

  • pH = 7-7.5 (can tolerate as low as 6.5, or as high as 8, but not ideal)
  • Water hardness/GH = 140-250 ppm/8-14°
  • KH/buffer = 53.7-143 ppm/3-8°
  • Ammonia levels in a successfully cycled tank should be = 0 (up to 0.25ppm for short periods)
  • Nitrite levels should also be = 0 (up to 0.5 ppm for very short periods)
  • Nitrate levels can fluctuate between = 0-40 ppm (however must be higher than 0 to finish cycling in the beginning).

To summarize, ammonia levels will spike in the beginning (2-4ppm is ideal), then will go back to zero when nitrites form (up to 2-4ppm maximum).

After that nitrates should form and nitrites should go down completely. Do 60-80% water change so that nitrates are at 10-40ppm before introducing your axolotl.

Important water parameters for an axolotl tank

Water pH levels

Axolotls are freshwater creatures, so they need alkaline water to thrive. pH levels of under 7 would mean that water is more acidic, while over 7 – alkaline. The most comfortable water pH for your axolotl is 7-7.40.

While your axolotl can tolerate a slightly lower or higher pH, you must always try your best to keep it at 7-7.40. The lowest pH allowed is 6.50, and the maximum – 7.5. They key is also to keep stable pH levels for your axolotl.

Water hardness, or GH

Axolotls prefer water that’s moderate to hard. Water hardness is the amount of dissolved calcium + magnesium in water. In practice, hard water causes limescale in kettles, pipes and cookware at home.

Make sure that water that you use for your axolotl tank is not soft. Otherwise, it can cause discoloration, especially discoloration of gills and anemia in your axolotl.

GH in your axolotl’s tank should be ideally between 140-250 ppm/8-14°. Both calcium and magnesium are often regulated in water, but in some cases, you might notice discoloration in your axolotl.

In this case, you will need to test your water separately for calcium and magnesium, to see if possibly one of the mineral levels is too low.

KH levels

KH is a measurement of bicarbonate and carbonate ions in aquarium water. It acts as a buffer and prevents pH levels from dropping suddenly, which is very harmful for an axolotl.

KH will neutralize acids in the tank, so that pH stays unaffected. Higher KH levels offer more ability to neutralize acids and prevent pH from dropping sharply.

KH levels are especially important if your pH in the tank is going down. In this case, raising KH will help neutralize more acid in the tank, therefore increasing pH as well.

Ammonia levels

Ammonia levels in a successfully cycled tanks and after that should be 0. As discussed above, ammonia will be produced from axolotl poop, dying plants and uneaten food that is in the tank.

Ammonia is highly toxic for your axolotl, that’s why in a brand new tank, you need to get rid of it before introducing your pet. Toxic ammonia will be neutralized in an axolotl tank by nitrifying bacteria, turning it into nitrites and then nitrates in a nitrogen cycle.

Ammonia levels should always 0, but can sometimes rise to 0.25ppm for short periods of time. While ammonia will be turned into less toxic substances, weekly water changes of around 20-30% of tank’s capacity are important to get rid of waste.

Nitrite levels

As discussed above, nitrites are ions that are intermediates in a nitrogen cycle in an axolotl tank. Nitrite levels should also 0 in an axolotl tank, as they are still toxic to aquatic life.

0.5ppm concentration for short periods of time is allowed. Nitrite is then turned into nitrates with help of nitrifying bacteria.

Nitrate levels

Nitrates are the end-product in a nitrogen cycle, of oxidization of nitrogen compounds. By the end of the cycle nitrates are ions that are not so toxic to aquatic life as beginning and intermediate ions.

Nitrates will stay in water until you perform a 20-30% water change every week. Please note, that water changes are a must, as nitrates are still rather toxic. To keep water clean, you will need to change water regularly.

Possible axolotl tank cycling issues

Guide on Axolotl Water Cycling, Nitrogen Cycle
Ammonia stays at zero when beginning the cycle in an axolotl tank

You can run into some issues when cycling your axolotl’s tank. For example, if your ammonia stays at zero when starting the cycle, that means that you didn’t add enough ammonia.

This could especially happen if you are using fish food or other creatures to produce waste in the tank. These methods are not very reliable and can take much longer.

Ammonia not being converted into nitrites in an axolotl tank

Another problem you might encounter is when ammonia is not being converted into nitrites. That would mean that you don’t have enough nitrifying bacteria in the tank.

Add more bottled bacteria (mentioned above). Also make sure that your filter is running constantly, and it must also contain biological media.

Ammonia is converted into nitrites, but no nitrates, in an axolotl tank

If you see ammonia levels dropping to zero or almost zero, and then moderate levels of nitrites, but no nitrates, your cycling isn’t moving forward.

In this case, that would mean that nitrite levels are too high. You would need to do water change (about 20-30%), so that levels drop to 1-3ppm.

Nitrogen cycle crashed fully in an axolotl tank

If your tank has suddenly developed high ammonia and possibly some nitrites, that could mean several things. The main reason would be that nitrifying bacteria are missing.

This could be because they were killed by adding water without dechlorinating it or adding some kind of antibiotic. Or, it could possibly mean that filter hasn’t been running for whatever reason.

Thank you for reading this post on preparing and cycling a tank for an axolotl. To read more post on axolotl care, please see this resource page.