Looking for a new aquarium project that’s a little different? Axolotls (Ambystoma mexicanum) are definitely not your average aquarium inhabitant. Although they’re sometimes referred to as walking fish, they’re are actually amphibians. Specifically: salamanders that are neotenic, which means they’re eternally ‘stuck’ in their fully aquatic larval stage and never lose their gills.
Did that capture your interest? We can imagine! Axolotl care is a little different than that of the aquarium fish you might be used to. We’ve put together a guide that contains everything you need to know about setting up an Axolotl tank and caring for these amazing creatures.
Here is everything you will need in order to set up a perfect Axolotl tank:
Choosing the right tank type is an important part of getting started with keeping any aquatic animal and it’s no different for Axolotls. Sadly there is quite a lot of outdated information out there about this species, including on tank size.
Contrary to what many sources will tell you, a 10 gallon aquarium is not enough to sustain an Axolotl in the long run. It might be an option for a single juvenile specimen if you’re planning on upgrading later, but since an adult size of 10 inches is not uncommon you’re better off just going for a larger set-up right away.
For a single Axolotl, a 20 gallon aquarium would work. Remember, a long tank is better than a tall one as these are bottom dwellers that have no use for vertical space. If you want to keep more than one Axolotl be sure to provide plenty of extra room: 10 extra gallons for every additional salamander is a good idea.
Every aquarium needs a filter. When choosing one for your Axolotl set-up, keep in mind that they don’t appreciate very strong water flow. A type that is easy to baffle the DIY way by tying a piece of sponge in front of the outflow is a good idea.
Axolotl keepers are fond of sponge filters, as they filter effectively without creating too much flow. You’ll need an air pump to run this filter type; be sure to get a high-quality and powerful one to ensure proper filtration. If your tank is going to be in a living area check the noise level beforehand, as some air pumps are known to be quite loud.
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Because Axolotls are a coldwater species that is actually very intolerant of high temperatures, you’re not going to need a powerful heater if you’re interested in keeping them.
We do always recommend using some type of heater just to prevent temperature swings between day and night, especially if the aquarium is in a room that often has open windows or doors and may be prone to changing temps.
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Water Test Kit
We can’t emphasize it enough: if you’re going to keep fish, you’re going to need a water test kit. No exceptions! A liquid (not strip) test kit that at least contains tests for ammonia/ammonium (NH3/NH4), nitrite (NO2), nitrate (NO3) and pH allows you to monitor your water quality and make sure it’s suitable for your Axolotl(s).
I highly recommend the API Freshwater Master Test Kit shown below. It is (by far) the best test kit on the market.
Take some time to select the right light for your Axolotl tank. Many aquarists are used to using strong lighting for optimal plant growth, but this is not the way to go with this species.
Axolotls don’t appreciate bright light at all and powerful lamps can stress them out. Instead, find something that allows you to see your Axies without scaring them into hiding all day.
Setting up Your Axolotl Tank
If you’ve just decided you want to get into Axolotl keeping, it can be tempting to run out to the aquarium store and buy one. Sadly, though, we have to encourage you to be patient a little longer.
Getting everything set up and ready before getting your ‘Axie(s)’ is crucial to keeping them happy and healthy. Introducing any animal into an uncycled aquarium can be disastrous!
Getting Started: Cycling Your Aquarium
Assuming you’ve got everything ready to go, you can now start setting up your Axolotl tank. Find a room in your home that stays cool year-round to avoid stressful times and overheating Axies during the Summer months.
Fill up your aquarium and turn on equipment like the filter and heater. If you want, you can also put all decorations (discussed below) in their respective places. After this it’s time to start the cycle!
Cycling your aquarium means you give it time to accumulate beneficial bacteria in the filter and substrate. These bacteria are the only thing making the tank safe for your future Axolotls, so it pays to put some effort into this.
To cycle an aquarium, you kickstart the process by adding ammonia. We prefer using unscented household ammonia as it’s easy to dose and doesn’t make a mess. Then, while adding more ammonia at the appropriate times, it’s a matter of simply waiting and testing. We won’t go too far into it here; if you’re not sure how to cycle, check out our complete fishless cycle guide for more info.
Axolotl Water Values
Like all aquarium inhabitants Axolotls do best in a certain range of water values and temperature. The latter is especially important: unlike what we’re used to with tropical fish, Axies are a coldwater species that won’t do well in warm water at all.
Your aquarium water should be around 64 °F for healthy Axolotls. Lower temperatures are not much of a problem, as the salamander’s metabolism will simply slow down. You’ll find the Axie getting sluggish in colder water, but there is no real issue.
Heat is much more dangerous and you should avoid temperatures over 75 °F at all costs. Overheating causes extreme stress in Axolotls, which can in turn lead to disease or even death.
Ammonia, nitrite and nitrate
These three are related to your cycle, which we discussed above. As you hopefully know by now, ammonia and nitrite should always be at zero as they are both deadly.
Nitrate is acceptable at low levels, but try not to let it rise above 15. If this does happen, perform a water change to reduce the nitrates.
The acidity or alkalinity of your water can be measured using your pH test. Axolotls can handle a relatively wide pH range: between 6.5 and 8 is acceptable, with 7.0 to 7.5 being ideal.
Axolotls like relatively hard water and your general hardness should ideally be at least 100ppm, with a maximum of around 200ppm.
Choosing a Substrate
Because Axolotls are bottom dwellers it’s a good idea to pay some attention to your substrate type. Most Axie enthusiasts agree that sand is the way to go for these amphibians. Carib Sea Super Natural Moonlight Sand works well.
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Some also keep Axolotls in bare-bottom set-ups for ease of maintenance, but there is some discussion on whether the lack of foothold can cause excessive stress. If you want to go the bare-bottom route, consider using slate or tile on the bottom of the tank to provide your Axolotl(s) with some extra grip.
Gravel, stones or marbles are a huge no-go for Axolotls. These salamanders see practically anything as food and are very clumsy during feeding time. There is a very real possibility of them taking a bite of substrate.
This is no problem if they’re kept on sand, but anything coarser can lead to big trouble. When ingested gravel can cause compaction and even death, so avoid it completely! It’s definitely not worth the risk.
Axolotls appreciate hiding places and will love some decor in the tank. Although not all standard aquarium decor will work there are still plenty of options to cheer up your Axie aquarium a little.
We love live plants – they don’t just look good, but they also help keep your water values stable. When choosing plants for your Axolotl tank, go for sturdy species. Axies aren’t the most mindful creatures around and they’re known to uproot or smash delicate greenery.
Additionally, it can be difficult to find species that can withstand the low temperature that Axolotls should be kept at.
Marimo moss balls are a crowd favorite for Axolotl tanks. They tolerate nearly any water temperatures, don’t require a lot of light, and are extremely easy to keep (just make sure your moss balls are large enough to not fit into a curious Axolotl’s mouth).
Here are some other plants that might work well:
- Java Fern
- Water Wisteria
- Anubias Nana
Floating plants might be helpful in creating subdued lighting.
A few well-placed pieces of driftwood make for a great natural look in your Axolotl tank and double as hiding places. Chunky driftwood without any sharp edges works best; avoid anything that the salamander(s) might get stuck in.
Cholla wood and Mopani Wood both look nice and work well.
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Complete your hardscape with anything from river rocks to dragon stone. As always, any rocks you use should be free of calcium and metals that might leach into your tank. It’s best to stick to store-bought if you’re not sure!
There are plenty of natural-looking hides on the market that you can use to make sure your Axolotl has a place to retreat to during the day. Try ceramic pipes, cichlid rocks or Pleco breeding caves.
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Axolotl Tank Mates
Should you keep your Axolotl alone or are there certain tank mates that might work? It can be tempting to stock your tank with multiple species (the more, the merrier, right?) but if you want to keep Axies this is unfortunately not going to be an option.
There are two reasons these salamanders should be kept in a single-species set-up:
- Danger to the Axolotl – Axies are quite vulnerable. For example, their delicate external gills can easily be damaged, even by fish species that are normally regarded as peaceful.
- Danger to the tankmate – As we’ll be discussing in the paragraph below, Axolotls are carnivores. As such, they pose a danger to small tankmates like schooling fish. While they might seem slow when they’re lounging around, you’ll be surprised to see how fast they can snap up unsuspecting prey! Some aquarists do keep their Axies with small species like minnows or guppies, but they are aware these tankmates will likely get eaten sooner or later.
Keeping multiple Axolotls together
Now that we’ve established that tank mates are a no-go in your Axolotl tank, you might be wondering whether it’s possible to keep multiple Axolotls together.
The answer here is ‘yes’, but unfortunately it’s not a straightforward yes. You’ll have to keep some factors in mind to successfully combine Axies.
First off, as we discussed earlier, you should keep tank size in mind if you want to stock multiple Axolotls. These salamanders can grow quite large and each individual needs its own space, so calculate at least 10 extra gallons for every additional Axie.
Too little space can result in squabbles where limbs are often lost and the weaker specimen might not survive. This especially applies when combining younger Axolotls or Axolotls of different sizes, neither of which is something you should try to do.
Always be careful, make sure every Axie has at least one hiding place and keep an eye on your water quality.
Axolotl Diet Guide
In the wild, Axolotls are predatory and will eat anything that moves/comes too close – think aquatic insects and worms, small fish, any land insect that has fallen into the water, other small amphibians and even (very frequently) their own eggs and smaller Axolotls.
What to avoid
When trying to figure out what to feed your Axolotl in the aquarium, there are a few things to keep in mind.
Although carnivorous, these salamanders aren’t exactly apex predators – they are quite clumsy and easily hurt by more aggressive prey. While their stomachs can handle a lot, very hard exoskeletons can cause impaction.
Axolotl guides and books used to regard warm-blooded animal meat like beefheart and liver as the ideal food choices, but hobbyists don’t recommend using these any more.
Also avoid the popular feeder goldfish, as they don’t contain the right nutrients for your Axies to thrive.
Here is a quick guide of foods you should avoid:
- Anything with a hard exoskeleton
- Beef heart and liver
- Any wild caught minnows (or similar fish)
Best Axolotl foods
There are high quality carnivore pellet types out there that work very well for Axolotls, so if you can get yours to eat these they make a great staple option. That’s exactly the problem, though: not all Axies are fond of pellets.
So what else can you try? Most Axolotl keepers agree that worms are one of the best Axie foods out there. This includes frozen worms like bloodworms, home-cultured species like blackworms, and (especially) earthworm. The latter is low in fat and high in nutrient content, especially when gut loaded beforehand using the nutritious pellets mentioned above.
As an added bonus, a worm lacks a hard exoskeleton or the power to hurt your Axolotl. Simply chop up larger worms to prevent issues and they make an ideal Axie food source.
In addition to pellets and worms, you can try feeding live guppies or minnows (home-bred to prevent disease and parasites), small insects, or some types of raw fish such as codfish.
Remove any uneaten food
Keep in mind that Axolotls are very messy eaters that can miss food that’s right in front of them, ignore food if it’s not wiggly and seemingly alive, and will spread pieces of food all over the aquarium.
Always remove any uneaten food within a few hours to avoid water quality issues! Leaving uneaten food in the tank will cause a lot of water quality issues (which is something that you definitely want to avoid).
Unfortunately, problems can arise in any area of the aquarium hobby and things are no different with Axolotls. We’ll discuss a few of the more commonly reported issues here.
As explained in the section on water values, Axolotls are not tropical creatures and won’t respond well to high temperatures at all. A heat stressed Axolotl will show white patches of mucus, particularly on the head. Additionally, it might vomit food back up or stop eating altogether.
Once an Axolotl has overheated all you can do is carefully bring the temperature back to the acceptable range, wait and hope any damage is not permanent. Best measure, thus, is to avoid overheating altogether. Consider whether the room you want to place your Axie tank in gets hot during summer and choose a cooler room if necessary.
Use chilling fans and air stones during the hotter months or even consider investing in an aquarium chilling system or air conditioning to bring the room temperature down.
Aggression and lost limbs
Axolotls are predatory and not at all picky about their next meal. A fellow Axie’s leg or tail can look very much like a tasty worm and in cases of overcrowding or keeping juveniles together these salamanders might end up taking a bite out of each other. Injuries can be fatal, so avoiding these situations is obviously best practice.
In cases of lost or damaged limbs that don’t seem grave, your best bet is to separate the Axolotl in question and maintain very high water quality in the quarantine tank until the wound has healed.
Axolotls can regenerate body parts like legs, tail and gills, which means that in most cases a lightly wounded specimen will be fine. Its new limbs likely won’t look as good as the old ones, but it’ll be able to live normally.
If your Axolotl has been severely damaged by one of its tankmates, you’ll have to take it to a vet. Not all vets will see aquatic animals, so be sure to find one and have their contact info ready before buying your Axie.
If your vet can’t see the wounded Axolotl right away, place it in a tub in the fridge to slow down its metabolism until it’s time for its appointment.
As discussed in the section on substrate, Axolotls are prone to eating small rocks and gravel, which can cause compaction. Additionally, compaction can occur if insects with hard exoskeletons are fed and the Axolotl’s digestive system is unable to deal with these.
What can you do in case of compaction?
Your best bet is to place the affected Axolotl in the fridge (surprising, I know…but hear us out). This slows down its metabolism, which results in its body attempting to get rid of any leftover foods as quickly as possible. This can work well in clearing its system.
You should start seeing pieces of poop in the container within a few days; if this is not the case you’ll unfortunately have to make a vet appointment to see what can be done.
Although Axolotls are neotenic (which means they don’t metamorphose in most cases), the switch can happen.
The Axolotl in question will slowly lose its gills and fins. Its eyes bulge and develop eyelids; it changes from being entirely aquatic to land-dwelling and air breathing. Its care requirements become similar to that of the terrestrial tiger salamander, another species often kept by amphibian enthusiasts.
So what’s the deal with metamorphosed Axolotls? If it’s not supposed to happen, then why do we occasionally see it?
In very rare cases, an Axolotl will metamorphose naturally. Usually, though, the process is the result of either hormonal treatment or living conditions that are so bad the Axie becomes land-dwelling to escape them.
Although irresponsible hobbyists are increasingly trying to force their Axolotls to metamorphose, it’s not something you should attempt. Individuals that metamorphose after reaching adulthood are usually short-lived and the ‘forcing process’ can be fatal (or at least unnecessarily stressful) in itself.
If you find your Axolotl changing, take a long and hard look at the conditions you’re keeping it in. Although freak incidents happen, most instances of metamorphosis are the result of less than ideal aquarium set-ups.
Axolotl aquarium maintenance is similar to ‘regular’ maintenance, so we won’t go too far into this.
The most important tasks are substrate vacuuming (after feedings and during water changes), water changes (weekly depending on your water test results) and filter cleaning (bi-weekly). On top of that, you might want to prune plants and do algae scrubbing where necessary.