Axolotl care

Water Changes for Axolotls (Hint: You're Doing it Wrong)

Water Changes for Axolotls (Hint: You're Doing it Wrong)

How often do you change your axolotl's water?

How much at a time?

What is the proper aquarium maintenance routine to follow so your pet stays healthy?

Great questions.

The answer is more than a simplistic broad-brush statement like "do a 90% change every week."

I mean, that can work, don't get me wrong.

But you might be making a lot of unnecessary work for yourself, or maybe even stressing your pet more than necessary.

Water Change Factors

Questions to consider when determining a water change schedule:

  • Do you have a filter for your aquarium? Filters can help you go far longer between water changes.
  • What kind of filter do you have? Not all filters are created equal. Some are more efficient than others. Still others may perform different functions.
  • Do you have healthy, live growing plants? Live plants (the right kinds, and the kinds that are thriving, not barely clinging to life) help do a lot of heavy lifting when it comes to purifying the water.
  • How heavily stocked is your aquarium? More animals equates to more waste.
  • What is your feeding routine? Heavier feeding equates to more waste, which turns into more "stuff" that needs to be processed
  • What temperature is the water? Warmer temperatures speed up the nitrogen cycle and cause certain plants to grow faster, resulting in more efficient nutrient processing. However, cooler water slows down the need for frequent feeding.
  • Are you buffering? Unless something is buffering the water, water changes are required to keep the pH within safe ranges.
  • What kind of ecosystem do you have? Some tanks are structured to help naturally process organic matter more than others.

Well, hopefully that didn't make things a million times more confusing.

But it's essential to understand how all these things work together to influence your water change schedule.

And why it isn't a one-size-fits-all answer.

Rather than blindly bailing out and refilling your axolotl's tank one or multiple times a week, I like to be more efficient with my time (and water) and do changes when needed only.

When to Change the Water

Say you've got a new tank (or tub) with no live plants, substrate, filter, nothing.

There is nothing to remove the ammonia put off by the animals.

So generally, more water changes are recommended.

Maybe even daily.

Now, say you've got a filter but you only got it a few days or a couple of weeks ago. So it hasn't had time to mature.

An uncycled filter is generally just as useful as having none.

(Until it gets cycled.)

What I recommend doing while you're waiting for it to mature, do water tests.

You don't need to guess.

The water tests will tell you when it's time to change the water.

Generally your two biggest enemies until the tank is cycled will be ammonia and/or nitrite.

If you see those start showing up on your water test, it's time to do a water change to get that back down.

You just want it to be faintly pink (or better yet none at all).

You will know your tank is FULLY cycled when you stop seeing ammonia and nitrite and you get nitrates.

Then your life can become much easier and you can reduce the amount of water changes and testing required.

Which brings me to my next point...

In established tanks?

Go by the water tests.

If you test your water and you notice:

  • Ammonia
  • Nitrite
  • Low pH
  • Nitrates over 40ppm

... that calls for a water change.

Old tank syndrome can happen in tanks that do not have some source of buffering or regular water changes.

That's why we test the pH weekly in such cases.

When the pH starts going down you know the tank is heading acid quick and needs you to interfere.

If you don't want to deal with worrying about a pH crash, a buffer can really help.

Some examples are crushed coral, oyster shells or other source of calcium carbonate.

These are usually placed in the filter or where the water is moving around.

How to Change the Water?

Large water changes may be necessary if you are having a parameter emergency or the water is really in bad shape.

Or maybe you're trying to cool down the water really quickly.

For large water changes, you can use a python (or even a submersible aquarium pump connected to some tubing) to drain a lot of water in a short amount of time.

The python is nice because you can use it to refill the tank.

Smaller water changes can be accomplished using a handheld siphon or a few feet of silicone tubing.

You can even use a turkey baster for spot cleaning (very useful, especially when maintaining tubs).


Don't use your mouth to start the siphon :P

You can use a rubber squeezer attachment that comes with some or dip the entire hose in the tank and fill it up with water to start it via gravity.

No Water Change Tanks?

Yes, it is possible to have a tank that does not require many or any water changes, only top-offs to refill after evaporation.

There are many aquarium keepers who own and maintain such tanks (myself included).

The key is to ensure all the parameters remain properly balanced.

After all, water changes aren't the only way to maintain good water quality for your axolotl.


Some may say, in the wild in a pond, water changes are a natural part of the axolotl's ecosystem.

Essentially, that nature does water changes - so we should too.

When it comes to water changes, I kinda find it a bit difficult to compare our aquariums to a lake that contains thousands of gallons of water.

Even so, evaporation and replenishing is not really a water change.

When evaporation happens, only distilled water is removed.

The organics, minerals and dissolved solids remain.

Rain is more of a top-off.

In a lake ecosystem, there are plants and small creatures and the substrate that all work to utilize the excess nutrients.

This can be implemented in the axolotl indoor home aquarium as well.

My belief is that as long as the parameters are within the proper ranges and the animal is healthy, you are probably being a good caretaker of the water.


I hope this posts helps save you some work or makes you think about something new :)

Water changes can be easier than you'd think.

Thanks for reading!

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