How to Care for Crayfish in Aquariums

Crayfish are a very unique choice of pet; keeping them is easy and fascinating. You can spend the whole day watching them eat, roam about in their tank, and digging burrows.


They’re small fish; the average size of one adult crayfish is approximately eight to ten centimetres.

Crayfish are a freshwater species — their natural habitats include ponds, rivers, shallow streams, and lakes.

Crayfish are somewhat related to the lobster. Lobsters are saltwater fish found in seas and oceans and are larger than their crayfish cousins. They’re both invertebrates. 

Keeping crayfish in an aquarium is simple. All you need to do is choose the species that you would like and either buy it from a reputable seller or get your feet wet and nab one from the wild (the local stream counts).

Some popular species of crayfish include: 

  • Blue Crayfish/ Florida Crayfish
  • Dwarf Orange Crayfish
  • Louisiana Crayfish
  • American Crayfish
  • Australian Crayfish
  • Miami Cave Crayfish 

Important steps in crayfish care include choosing the right aquarium, proper feeding, properly selecting tankmates for your new pet, and knowing when to change the aquarium water. 

We made a crayfish care guide below so you can be well prepared to begin this journey.

Choosing the Right Aquarium 

As with any pet, crayfish need to have the right aquarium considering that’s where they spend all their time in your home.

Invest in a tank that’s big enough and comfortable for your crayfish.

Below are some pointers to guide you on the type and set-up of an aquarium for these fish. 

Freshwater Aquarium

A freshwater aquarium is a must-have because that’s the natural habitat of crayfish species.

If you make the mistake of putting them in a saltwater aquarium, they won’t survive. 

Size of Aquarium

The freshwater aquarium should be a five to ten-gallon tank.

This is for a single crayfish. If you want to have more than one crayfish or other fish as well, add an extra 10 gallons to the tank size per fish.

These freshwater fish need their space, so be sure to oblige.

Water Temperature and pH 

The water temperature should range between 69 to 75 degrees Fahrenheit and a neutral pH level of about 7.

It should also be filtered because crayfish don’t do well in polluted water. These are the optimum temperatures and conditions for their survival. 

If your water pH is low – meaning it’s acidic- here’s a handy guide on how to raise the pH to a more neutral level (7).


The water in the aquarium shouldn’t be too deep; 6 inches is good enough.

The deeper the water, the less oxygen the crayfish can access. If you have a bigger tank, add an aerator to add oxygen so the crayfish can survive. 

Have an Aquarium Lid

Your freshwater aquarium should have a lid because crayfish can be crafty.

These creatures will take any chance they get to climb out of the tank and wander around, so never leave the lid open and the aquarium unattended to.

Add Some Nooks for Hiding

Put in some natural features and additions like moss and rocks at the bottom of the aquarium. You can improvise with plastic or ceramic pipes. 

Crayfish like a good game of hide and seek, so adding these features keeps the fish comfortable, and they can hide away when they need it, especially during molting.

Plants are important in an aquarium because they produce much-needed oxygen that your crayfish will need.

They also take in nitrates and any harmful waste that can harm your fish. Check out these low-maintenance plants for your crayfish aquarium.

Have Another Aquarium for When They Molt

When a crayfish molts or sheds its shells, move it to another tank (that is, if it has tankmates). This is because it’s vulnerable to attack from other species – it’s soft, and the new shell takes two to three days to harden.

Molting happens 3 to 5 times a year for adult crayfish and up to ten times a year in younger ones. The reason for the difference is the younger ones are yet to have a mature shell and have to go through the molting cycle more. 

The period between molting depends on various factors; the crayfish’s age, living conditions, oxygen levels, and the population of the crayfish in the aquarium. 

This process is similar to a snake shedding. During this time (before and after molting), your pet will barely eat any food. Instead, they’ll feed on their old shell to assimilate the nutrients.  

If it’s in a tank alone and is about to molt, leave it be.

If it’s in a tank with other crayfish or any other species of crayfish, separate it for its safety. 

Knowing What to Feed Your Crayfish

Crayfish are omnivorous; their diet consists of both flesh and plant matter. They also eat decomposing matter like dead animals and insects.

Feeding crayfish once a day is sufficient.

Some of the things that they consume include: 

  • Regular fish feed in the form of powder, flakes, or pellets.
  • Chopped up vegetables like cabbage, carrots, and peas.
  • Small insects and fish like shrimp, worms, and snails.

Crayfish feeding hours may vary; they may not eat during the day and come out to eat at night.

That shouldn’t stop you from dropping the fish food into the tank; your little friends will feast on them later in the day. 

It may be tempting to overfeed your crayfish but don’t. Regular overfeeding causes the shell to weaken over time, which will be dangerous because it won’t be able to defend itself in case of an attack. 

Select Tank Mates Wisely

It’s best to keep a crayfish alone in a tank because of how aggressive this species can get.

Two or three crayfish in the same tank isn’t bad. However, they may get territorial when they’re molting and go as far as eating each other. 

If you choose to keep other crayfish, that’s well and good; just be sure that they are of the same species to avoid aggression. In addition, always transfer the ones that are molting into a different tank or aquarium to prevent incidents. 

Despite the aggressiveness, crayfish may coexist with several fish species. Some good choices include: 

  • Barbs
  • Minnows
  • Hatchetfish
  • Cichlids
  • Rasboras

One similarity of these fish species is that they swim fast, so if your crayfish decided to be aggressive, they wouldn’t be able to catch them.

Also, be sure to get the largest and most robust varieties of these fish to give them a better chance of warding off aggression from your crayfish.

Some fish to avoid in your aquarium as crayfish tank mates include plecos, catfish, loaches, freshwater snails, shrimp, and betta fish. These fish are either bottom feeders or slow-moving, and there’s a chance that your crayfish will snap them up for dinner!

Here are some excellent resources on dealing with aggressive fish, in case you need to play referee with your crayfish and its tank mates. 

Frequency of Changing Water

Freshwater crayfish need fresh water. The water should have a neutral pH of seven, be filtered and well aerated. 

Crayfish release a lot of waste materials and hide food under rocks and in burrows. The food rots after a few days, and the water conditions in the aquarium will deteriorate fast. You’ll need to change the water often. 

The best way to do it is to change a certain percentage of the water every week instead of emptying the whole tank.

Below is a simple table to show you how often you need to change the water of your crayfish aquarium.

Size of AquariumFrequency of Water Changes
5-10 gallon tank (one crayfish)Change 50% of the water at least weekly (2.5 to 5 gallons)
20+ gallon tank (more than one crayfish)Change 25% of the water weekly. 
(4 gallons +)

The bigger the filtered tank is, the less often you’ll have to change the water. You can always use your trusty eyes to look at the state of the water.

If it’s dirtier even before the next water change—don’t wait, just change it.  

Keeping Crayfish in an Aquarium Is Quite Easy

A crayfish is one pet that you’ll never regret having, and you’ll both enjoy each other’s company.

As an aquarium enthusiast who’s had one for years on end, my joy lies in sharing all the information I have and learning new things in the process. 

For access to this reserve of priceless information, visit Aquarium Sphere today and swim around; there’s something for all aquarium lovers and fish keepers.

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