Can You Put 2 Crayfish Together?

Can You Put 2 Crayfish Together

When you’re just starting as a crayfish keeper, you might really want to keep more than one crayfish. Though it is not advisable, keeping multiple crayfish together is not impossible. However, you’ll really need to know what you are doing.

You can keep 2 crayfish together in at least a 20 gallon tank. There needs to be multiple hiding places and at least 2-3 inches of substrate for digging.

Though keeping more than one crayfish in a tank is possible, you’ll need to take care of multiple things for that. Let’s go through them in details.

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blue crayfish roaming inside tank
Owner: Cassica Milleville

Things You Need To Know For Keeping Multiple Crayfish Together

In this section, I’ll talk about 5 things that will help you to keep multiple crayfishes together. Think of these 5 things more as a guideline or principle so that you can understand crayfishes better.

Let’s start with the most important one when keeping crayfishes:

1. Enough Space

Crayfishes are extremely aggressive and territorial. So, if you want to keep more than one crayfish, you’ll need to provide them enough space. The crayfishes will fight each other to death if one enters the other’s territory.

A good rule of thumb is at least 10 gallon of swimming space for one crayfish. So, if you want to keep 2 crayfish, make sure they are in a 20 gallon tank at least. The larger the tank, the better.

One important thing to note is, just higher volume won’t do for crayfish. They need a large surface area for digging and exploring.

In the nature, one crayfish need about 2 square feet of space for living peacefully. Here I’m giving the measurement of two tanks:

  • 24 x 12 x 16 cubic inch
  • 30 x 12 x 12 cubic inch

Both measurement results in a 20 gallon tank. However, the first one has a surface area of 288 square inches. The second one has 360 square inches of surface area.

Can you guess which one will be better for keeping 2 crayfishes?

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If you guessed the second, then you’re right!

As I’ve said, crayfishes need a larger surface area for digging and exploring as well as establishing their territory. So, the larger surface area you can provide, the better.

This is especially important for keeping multiple crayfishes together.

2. Enough Substrate

I’ve already talked about digging. Crayfishes love to dig. It’s one of their natural instincts.

Digging helps the crayfish to make a hiding place where they can feel safe, establish & mark their own territory. So, you’ll need to provide enough substrate so the crayfish can dig comfortably.

It is better if you can use sand type substrate as they are better & easier for digging. I’ll suggest to put at least 2-3 inches deep substrate layer for enough digging space.

If you still want to know more about substrate for crayfish, don’t forget to check out my detailed guide on it. Hopefully everything will get clearer after reading that!

crayfish closeup
Owner: Anthony Schemel

3. Enough Hiding Places

I can’t stress how important hiding places are for keeping crayfish. Even if you keep just one crayfish, make sure there are hiding places.

Crayfishes are natural scavengers and most of the time they are hunted down in the nature by other larger prays. So, they like to hide themselves. It is necessary for their healthy & stress-free living.

That’s why we need to make sure there are enough hiding places, especially when more than one crayfishes are in the tank.

Personally, if I am keeping 2 crayfish in a single tank, I’ll make sure there are at least 4-5 good hiding places. Making hiding places don’t need to be expensive at all.

Moreover, if you are good with DIY, then you can make some for free with regular household items.

Here are some ideas:

  • I like to use rocks and woods as the hiding places. If you are creative enough, you can glue multiple rocks together into a cave shape. These cave like structures are excellent as hiding places and they also look very natural & realistic. So, if you prefer looks, then making caves out of rocks & stones can be a pretty good option.
  • If you don’t have the patience to glue rock together, you can get some cheap hiding places. You can find some good options here on Amazon.
  • Another cheap option can be PVC pipes. Just get some PVC pipes, cut them out in 5-6 inches length and throw them in the tank. The crayfishes will use these PVC pipes as hideout. Extremely cheap yet effective option for beginners!
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If you want to use woods/stones from the nature, make sure to treat them before using in the tank. Here’s how you can do that:

  1. First, clean the stones under running water. Make sure all the dirt is gone. You can also scrub the surface if necessary. Hot water will be much more effective than cold water.
  2. After cleaning the stones under running water, I like to treat them with a hydrogen peroxide solution. This ensures all the germs are dead and the stone is 100% safe for the crayfish.
  3. This is just an extra step and not mandatory. However, I like to follow this to be super sure. Just take your stones and boil them for 1-2 hour. This will pretty much guarantee nothing unwanted is being introduced to the tank with your stone.

4. Two Females Rather Than Two Males

Male crayfishes tend to be more aggressive than the females. It’s because the male ones are more territorial.

So, if you are planning to keep 2 crayfishes together and if you have no plan for breeding, I’ll suggest to keep 2 females rather than 2 males.

As the females are much less aggressive than the male ones, chances of aggression between the two will be much lower.

5. Keep Them Fed

Crayfishes generally go out of their way to look for food and fight when they are hungry. If they are properly fed, generally they don’t tend to fight. So, try to keep your crayfishes properly fed.

However, that doesn’t mean you’ll need to feed them 2 times per day. Proper feeding and overfeeding are two different spectrums.

Crayfishes are natural scavengers, so they’ll look for uneaten foods, plants or other organic matters and eat those. As a result, there is no need to feed them everyday.

I like to feed my crayfishes every other day. This ensures they are not overfed and the water quality isn’t getting deteriorated.

You can check out my detailed crayfish feeding guide to know what I feed my crayfish and how much I feed it.

orange berried crayfish with eggs on white substrate
Owner: Mary Kot

How Many Crayfish Can Live Together?

Generally, one crayfish need 10 gallons of swimming space for living peacefully. However, that doesn’t mean you can keep 3 crayfish in a 30 gallon tank.

It is never a good idea to keep more than 2 crayfishes, unless you have at least a 55 or 60 gallon tank.

As I have mentioned earlier, along with swimming space, crayfishes also need a large surface area for digging, exploring and establishing territory. So, I don’t think a 30 gallon tank will be enough for 3 crayfishes in any way and soon you’ll see them fighting.

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Can A Male And A Female Crayfish Live Together?

Yes you can keep a male and female crayfish together provided that you’ve done all the things that I’ve mentioned earlier. However, if you are keeping a male-female pair, expect them to breed when they get sexually matured.

When the crayfishes breed, soon you’ll see the tank is filled with baby crayfishes. The adult crayfishes tend to eat the babies. So, you need to separate the babies or the adult ones. Also, babies require extra care and attention.

If you are not ready for the hassle of breeding, I’ll recommend to get two females instead of a pair.

Determining Crayfish Gender: Infographic

how to determine crayfish gender infographic

Want to get a printable version of this infographic? Click here! [If you want to use this infographic on your website, please link back to this post as the source!]

Your Crayfishes Might Not Get Along Forever

Even if you follow all the steps I mentioned above, there is no guarantee that your crayfishes will get along with each other forever. As crayfishes get older, they tend to get more aggressive and territorial.

So, even if 2 baby crayfishes get along fine, that doesn’t mean they will when they get older. That’s why you’ll always need to have a contingency plan and keep a separate tank ready for any unavoidable circumstances.

Frequently Asked Questions

How many crayfish can you keep in a 20 gallon tank?

You can keep one or two crayfish in a 20-gallon tank. However, if you want to keep two crayfish together, you will need at least a 20-gallon tank with multiple hiding places and at least 2-3 inches of substrate for digging.

Can crayfish and crabs live together?

Despite being in the same family of crustaceans, crayfish and crabs can hardly coexist due to potential fights caused by the crayfish’s tendency to stir up trouble.

Will crayfish eat other crayfish?

Crayfish will eat other crayfish under certain circumstances, such as when food sources are scarce or when they are in overpopulated tanks.

Crayfish are very aggressive and territorial, and they will kill and eat any animal they can, including other crayfish.

Final Words

By now you know, keeping 2 crayfishes is not impossible but require a lot of hassle. If you are not ready for all of these, I’ll advise to stick with just one crayfish. This is especially recommended if you are a beginner.

Muntaseer Rahman

About Author

Hello, I’m Muntaseer Rahman, the owner of I’m passionate about aquarium pets like shrimps, snails, crabs, and crayfish. I’ve created this website to share my expertise and help you provide better care for these amazing pets.


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