How to Set Up a Crayfish Tank

Setting up a crayfish tank is pretty easy. In most cases, it really does not matter much which species you want to keep, for example, it can be Procambarus alleni, Cherax destructor, Brazos Dwarf Crayfish, Dwarf Mexican crayfish, Procarambus Clarkii, Marbled crayfish, etc. the process and principles will be the same.

Generally, crayfish are extremely hardy pets which makes them great for the beginner aquarium hobbyist. There is also no need for a fancy setup or extra aquarium equipment.

All we need is a standard aquarium, an inert substrate on the bottom of the tank, an aquarium filter, and an air pump. Fill it with water. Wait until the nitrogen cycle finishes and add crayfish to its new home. Sounds simple, isn’t it?

In this article, I will approach setting up the crayfish tank in the steps below covering the most important ones.

An Introduction to Crayfish Keeping

Although crayfish are a somewhat unorthodox pet, more and more aquarists are giving crayfish keeping a try. Their active nature and appealing personality make them one of the most interesting aquatic pets.

Crayfish are very curious and bold creatures. So, when anything goes into the tank, they will likely come closer to check it out!

Setting Up Your Crayfish Tank

Step 1: Choosing Your Crayfish Tank

Depending on the crayfish species, you will need at least a 10-gallon tank (40 liters) for small crayfish (like Brazos Dwarf Crayfish, Dwarf Mexican crayfish), and a 20-gallon (80 liters) tank for bigger species (like Procambarus alleni, Cherax destructor, Procarambus Clarkii, Marbled crayfish).

In any case, if it is possible, I would always recommend the bigger tank and there are two main reasons why:

It would be the best and most forgiving of the occasional (beginner) mistakes in the tank’s water
It will reduce potential aggression towards other crayfish if you decide to keep several of them. Always remember that crayfish are usually aggressive and territorial. Although there can be some exceptions to this rule, there are no guarantees of peaceful cohabitation.

Important: You will also need to make sure that there is a tight lid on the tank because crayfish can climb very well. They are amazing escape artists and strong enough to even push aside loosely-fitting cover!

Step 2: Cleaning, Testing, and Painting Crayfish Tank

It always surprises me but it seems like I am one of a few aquarists who actually constantly talks about cleaning and testing tanks before using them. Unfortunately, most hobbyists are so eager to start that they simply skip it.

DO NOT underestimate this step! It can be absolutely spirit-breaking after setting up your aquarium to find out that it is leaking or there is some kind of residue which is toxic to any crayfish, fish, shrimp, or snails.

Cleaning is very simple. For example, we can use hydrogen peroxide (this is a cheap and handy household supply that is often used for cleaning and disinfecting). Spray it on the walls, and let it sit for 10 – 20 minutes. Next, wash it off properly (do it at least twice to remove hydrogen peroxide). No soap!
Note: Use gloves before you start cleaning the
Testing is also very easy to do. Put some paper underneath the tank, fill it with water, and leave it for 1 day. If you do not see any wet spots on the paper, the tank is safe.

Painting. Strictly speaking, painting the back (outside) of the tank is not absolutely necessary. However, I would strongly recommend doing that anyway. The point is that according to different studies, a dark background can significantly improve your crayfish, crab, or shrimp coloration.

Tip: In my opinion, the easiest way is to spray-paint the tank. Use adhesive tape to prevent painting the sides of the tank.

Tip #2: If you do not want your paint running, spray a thin layer of paint and let it sit for a few minutes. Then, spray a full cover.
You can read more about “How to Enhance Shrimp Color?” right here.

Step 3: Adding Substrate to the Crayfish Tank

The substrate refers to whatever you are going to put on the bottom of the tank.

Substrate is essential for crayfish as they like to dig it and often bury themselves in it. In addition, it hosts loads of beneficial bacteria, that will help stabilize your water parameters.

Although there are lots of options on the market, in most cases, just sand or small gravel will be the best choice.

The substrate should not be too thin or too deep, for example, 3 – 4 inches (or 7 – 10 cm) will be good enough for most crayfish species.

Using Sand as Your Substrate

Crayfish enjoy burrowing and digging. Crayfish can also rearrange the substrate to make small mounds or to make caves to hide in. Sand would be the best substrate for crayfish due to their burrowing and digging needs.

Sand comes in a variety of different colors. You should keep the color of your crayfish in mind when picking a sand color. There are some species of light-colored crayfish that would stand out wonderfully with a black sand backdrop.

Darker-colored species may also stand out with a lighter-colored sand backdrop. Sand requires more work than gravel due to rinsing needs. You will also have to wait for the sand to settle in the tank before adding your tank residents to the tank. However, sand is a great substrate for a crayfish tank.

For example, (link to check the price on Amazon):

Sand Substrate: CaribSea Super Naturals Crystal River Sand

Using Small Gravel as Your Substrate

Using small gravel as your tank substrate still allows your crayfish to burrow, dig, sift and rearrange everything to their liking. In addition, gravel comes in a variety of different colors. This makes gravel a great choice aesthetically for any tank.

For example, (link to check the price on Amazon):

Gravel Substrate: Seachem Flourite Black Clay Gravel

Would Soil Substrates Be Suitable for a Crayfish Tank?

Although soil substrates are often active substrates, it means that they help maintain the low pH and soft water. It is still possible to keep crayfish in such tanks.

Just keep in mind that too low pH and very soft water can cause molting problems for your crayfish.

Would A Bare Bottom Tank Be Suitable for Crayfish?

Whether you choose sand or gravel, it is recommended to have a substrate in your tank. You do have the option of keeping your tank bottom bare. However, you will lose out on watching the crayfish act as they normally would in their natural habitats.

On top of that, I can also add that your crayfish will be very unhappy and stressed. Therefore, unless it is a quarantine tank, I would never recommend a bare-bottom tank for crayfish.

Prepare the Substrate

Do not forget to clean and rinse sand or gravel to get rid of any debris or dust that might have accumulated on it. If you forget to rinse your sand, your tank can turn into an uninhabitable cloudy mess.

You need to remember to clean and rinse the sand or gravel before adding it to your tank. You can’t skip this step. Sand will normally turn tank water cloudy but it will settle over time. If you do skip rinsing the sand, your tank can become a cloudy mess that won’t settle.

Note: Even if you see on the bag it is marketed as “pre-rinsed” or “pre-cleaned” by manufacturers. DO NOT believe them. Although the substrate itself can be clean, the bags often contain dust, debris, or other residues. We do not need any of that in our tanks.

How to Prepare Sand

You can put your sand into a bucket and spray the sand with a hose.
The excess water will run out of the bucket and the water will be cloudy and dirty initially.
With continuous rinsing, you will begin to notice that the water will run clearer.
A clear stream means that the sand is ready to add to the tank.
Important: When you think that sand is absolutely clean – rinse it again! It is not a joke. Sand has lots of tiny detritus particles.
It is easiest to add sand to an empty tank. Use some sort of surface, such as plates, to prevent stirring up the sand when you begin to fill the tank with water.

How to Prepare Gravel

Place the gravel into the bucket.
Fill the bucket with tap water. The water should completely cover the gravel.
Stir and move the gravel around (use a stick if necessary).
Leave it in the bucket for 5 – 10 minutes. It will soften up any dust and debris that may be on the gravel.

Step 4: Adding Decorations and Plants

Decoration

Sometimes hobbyists intentionally do not add decorations to the tank. They do that so they can easily see what crayfish is doing in the tank. They are wrong and do more harm to their crayfish!

Driftwood, rocks, and decorations are essential parts of a successful crayfish tank. First of all, it will replicate their natural environment, therefore, it will let them feel at home.

Second, we need to provide lots of hiding places to reduce stress (during molting) and territorial battles. If the tank has a lot of secluded places, even in crowded tanks, it will be rare for any specimens to lose a pincer. Otherwise, they can seriously harm (or even kill) one another.

That is why adding decoration here and there is not just recommended, it is vital.

Tip: If you are planning to have a budget set up for your crayfish, use PVC pipes. They are dirty cheap and crayfish love them! The only downside is the way they look.

Examples (links to Amazon):

Plants

In the wild, crayfish are often found in dense vegetation. According to some studies, crayfish densities were consistently higher in marsh habitats dominated by plants. So, some aquarists may believe that their planted tanks will be a great place for the crayfish.

Do not make this mistake!

Unfortunately, most crayfish species and planted tanks are not compatible (except, dwarf crayfish species like Brazos Dwarf Crayfish, Dwarf Mexican crayfish).

Adult crayfish will eat, cut, and uproot any plant in the tank it can get. They are absolutely not plant safe. In such limited space as our aquariums, crayfish become lawnmowers and there is nothing we can do about it.

So, unless you are ready to buy some cheap plants and keep replacing them once a month or so, you will not see any plants in the tank.
Note: The only plants that crayfish tend to leave alone are floaters because they simply cannot get there or fake plants.

For example:

Fake plants (link to Amazon).

Important: If you decide to add fake plants, take a look at the material they are made of. Avoid soft plastic or soft rubber. Crayfish will try to chew and eat it.

Read my article about “Top 7 floating plants for beginners”.

Be Warned: Not Every Rock or Decoration is Safe for Your Crayfish Tank

Make sure that any rock or decoration that you put in your tank is aquarium safe. You are not alone if you have ever thought about taking a random rock from outside and putting it into your tank as decoration.

However, foreign rocks can actually be extremely harmful to your tank. The rocks may contain unseen bacteria which can affect your crayfish. The rocks may also leach unwanted substances into your tank.

Here is a word of caution for those who have thought about adding outside rocks to their tanks.

I have seen tutorials where people say to boil the rocks to prepare them for the tank. The tutorials claim that boiling the rocks will get rid of any nasty residents that may enter your tank. While this is true, the gas created from boiling the rock may be poisonous to humans depending on what is actually on the rock.

I would advise you to buy rocks and decorations that are already deemed to be aquarium safe.

Step 5: Install Your Filter

All aquariums need filtration – and the crayfish tank is no different. The filter performs 2 main tasks:

Cleans up floating debris.
Harbors beneficial bacteria that allow your tank to cycle and become a healthy ecosystem.

There are several most popular types of aquarium filters out there (Canister filters, hang on the back filters, and sponge filters). Each of them has its own pros and cons.

Canister filter is the best choice for water quality, canister filters have room for lots of filter media. Opposite to the sponge filter, this option is ideal for fresh shrimp tanks that are over 20 gallons.

Nonetheless, when we are talking about a filter for crayfish tanks I would recommend mostly canister or hang on the back filters instead of sponge filters.

One of the problems is that crayfish have strong claws and can/will tear apart sponge filters with time. Another problem, they will chew and try to eat small pieces of sponge. It can be detrimental to their health.

That is why there are only two options here – Hang on the back and Canister filters.
Tip: if you have a 10-gallon (40 liters) tank, choose the filter, which is rated for at least 20 gallons (80 liters). The difference in money is minimal but the benefit is huge!
Some examples (links to Amazon):

Step 6: Install Your Air Pump and Heater

In nature, crayfish crawl out to the land from time to time. So, if the aquascape in your tank does not allow your crayfish to get to the surface, I would definitely recommend adding a bubbler.

Many crayfish species need oxygenated water. Do not forget about it.

Whether you need a heater or not depends on the crayfish species. So you have to know the correct one that your species require. In most cases, they do not need it.

However, if there are temperature fluctuations in the place you live, it can be a good idea to have a thermostat heater. Thermostat heaters work by maintaining a set temperature. Once the temperature goes below a certain degree, it turns on.

Important: Unlike filters, only choose the heater appropriate for your tank size. If the heater is larger than what your tank actually requires, it may lead to overheating and ultimately – the death of all your crayfish.

Note: Use only adjustable heaters. If you have a preset heater in your tank and it’s not heating it to the proper temperature, then there’s no way of adjusting it if it’s preset.

Check one of the cheapest and most popular air pumps (Tetra Whisper Easy to Use Air Pump for Aquariums).

Step 7: Installing Aquarium Light

No special requirements. Crayfish are mostly nocturnal creatures, they will not be bothered about the kind of light you use.

Basically, the lighting is mostly up to your taste and how well you want your tank to be illuminated. If you have floating plants in a crayfish tank, lighting should be adapted to their needs.

Step 8: Filling up the Aquarium

Place a plate on top of your substrate, and pour water on top of the plate to fill your tank. Using a plate will prevent disturbance. Frankly saying, you will still get some clouding issues. However, it will not be a complete mess.

Step 9: Cycling Your Crayfish Tank

This is the most important step if you skip this step your crayfish will not make it long.

To put things simply, all living beings create ammonia when they poop or pee. Ammonia is toxic to crayfish and ammonia levels can build up over time. This can lead to your crayfish dying if the ammonia has nowhere to go. This is why you need to cycle your tank before adding crayfish.

Nitrogen cycle is the process of the development of beneficial bacteria in the filter and substrate that can turn toxic wastes into a less harmful end product that can be removed with regular water changes.

How can we cycle the crayfish tank? There are two ways:

We can sit back and be patient as the tank will have to cycle for a month or more by itself (naturally).
We can add some beneficial bacteria to boost the cycling process. In this case, it can take several weeks.

Step 1

The first step to cycling is adding ammonia to the tank. This sounds backwards but adding ammonia will cause ammonia eating bacteria to appear. Use 100% ammonia when adding ammonia to your tank. Normal household ammonia will not work.

Follow the ammonia guidelines that come with the product. Wait an hour and then measure your ammonia levels with an aquarium test kit. For tanks with less than 40 gallons of water, you will want your ammonia levels to be around 2ppm.

For tanks with more than 40 gallons of water, you will want your ammonia levels to be around 4ppm. Having lower levels of ammonia than needed can be remedied by adding more ammonia.

If your levels are too high, you can do a 20 percent water change. That will help your levels balance out.

Step 2

Test the ammonia levels each day. The levels will drop when nitrites have gathered to remove the ammonia. These nitrites are still dangerous to your crayfish.

Add half the amount of ammonia that you added originally. This will keep your nitrites alive so that you don’t have to restart your cycle. Your nitrite levels will continue to rise. Eventually, they will start to drop.

Step 3

You are now in the final step of the cycling process. Nitrates have formed instead of nitrites. You may continue adding half the amount of ammonia. Try to keep the ammonia levels around 2ppm.

You will know that your cycle is done when both ammonia and nitrites reach zero when 24 hours have passed after adding ammonia. You can double-check to see if your cycle is done by adding the original amount of ammonia that you used the first time. The ammonia and nitrite levels should be back to zero after 24 hours.

Some recommended products (links to Amazon):

Water Testing Kit

An important tool for monitoring your cycle is a water testing kit. Without a test kit, it will not be possible to estimate the real condition of the growing nitrogen cycle (ammonia, nitrites, and nitrates, which are poisonous to crayfish). In other words, you are pretty much flying blind and hoping for the best.

Therefore, the test kit is a must-have tool! It should be one of the first things you buy. It is critical in the hobby to make sure everything is okay in your tank and that it is a healthy environment for your crayfish.

There are 2 types of test kits: the test strips and the liquid tests. Personally, I would highly recommend using a liquid test as they are more accurate than the test strips.

Recommended product (links to Amazon):

API Master Test Kit (check the price on Amazon).

Step 10: Adding the Crayfish to the Tank. Acclimation

Once the cycle is complete (you should not have nitrates), do not rush to add the crayfish to the tank.

To be safe, I would wait at least 1 week more. Keep checking the water parameters daily. You need to be absolutely sure that they are stable and that there are no sudden ammonia spikes.

When you bring your crayfish home, it should come in a plastic bag or container of water. Do not put your crayfish directly in the tank! You can shock the system of your crayfish by changing water parameters and temperature too quickly.

To avoid it, you need to acclimate them the right way. Read more about it in my article “How I Drip Acclimate Shrimp and Why” the principle is absolutely the same.

Keeping Crayfish and Water Parameters

Crayfish are usually straightforward and easy to care for. They are hardy animals and can live in a wide range of water parameters.

However, for optimal results, it is best to keep your nitrate levels near 0 ppm. The pH levels in your tank are also extremely important. Crayfish prefer pH 7.0 or 8.0. Although they can live even in slightly acidic water, it is not good for them in the long run.

The point is that low pH levels will cause the shell of crayfish to become softer than it should be. This is because their shells are composed of calcium carbonate which reacts with acid. So, crayfish will have trouble keeping their shells in the right condition when the water in the tank is too acidic.

Very high pH may also increase the toxicity of other substances. For example, the toxicity of ammonia is ten times more severe at a pH of 8.0 than it is at pH 7.0.

You will have to research your specific species of crayfish in order to know what temperature to keep in your tank. On my blog, you can find guides on the most popular aquarium crayfish species.

Some species of crayfish enjoy cooler temperatures. They can survive in tanks with temperatures as low as 65 degrees Fahrenheit.

Other species are less tolerant of cold conditions (for example, Cherax destructor). They can only survive in temperatures between 75 to 82 degrees Fahrenheit (24 – 28 C). Most freshwater crayfish fall into this more tropical category.

Tankmates and Crayfish Compatibility Issues

Crayfish are not the nicest of tankmates. They have an aggressive nature that makes them unsafe to be housed with many types of fish. It is important to research what tankmates may be compatible with crayfish before adding them to the tank.

Fish

Small fish may end up being hurt or eaten as a snack. Although crayfish are not fish predators per se but are opportunistic fish scavengers and will consume fish that are small, defenseless, or weak.

Note: Thing is, most fish species are most vulnerable at night while resting near the substrate and that is exactly the time crayfish are most active.

Housing crayfish with fish that are larger than them or more aggressive puts the crayfish at risk of becoming a target for these fish. For example, Pea puffers may look so cute and innocent but, in reality, they are cunning and voracious little predators. Pea puffers are merciless and dedicated hunters, with an endless appetite for your snails, shrimp, crayfish, or crabs.

Related article:

Can You Keep Crayfish With Other Fish?

Shrimp

Unfortunately, even dwarf crayfish species will be dangerous for shrimp. They can easily overpower shrimp. In addition, any molting shrimp is an easy meal for a crayfish. If crayfish gets hold of a shrimp, the shrimp usually does not have any chance.

Even baby crayfish can try to catch shrimp. Therefore, keeping them together with dwarf shrimp should be avoided. Nonetheless, if you agree to lose one or two shrimp here and there you may be good to try.

Note: In my guides about dwarf crayfish species, I never recommend keeping them with small shrimp. Except maybe Ghost shrimp, Amano shrimp, Bamboo shrimp, and Vampire shrimp, these species can grow bigger than Brazos Dwarf crayfish and should be relatively safe.

Snails

Snails are also not good tankmates for crayfish. They will definitely try to catch slow-moving snails. So, they should not be trusted with anything smaller they can catch.

Large snails are also not safe in crayfish tanks. You will often see them without antennas, it is easy to guess why it happens. Basically, all freshwater snails are also not a good match to be crayfish tank mates.

Dwarf Frogs

Do not keep Dwarf frogs and crayfish together. Frogs have very sensitive skin that can be easily damaged by crayfish. When the frog gets weak, crayfish will catch and eat it.

Crayfish

In addition to compatibility issues with other species, crayfish can be aggressive with each other. This is especially true when crayfish have to share tight quarters with each other.

The crayfish may become more aggressive as they fight for territory and resources. Crayfish need hides in order to prevent aggression issues.

As we can see, most crayfish species are not completely safe and peaceful with other tank mates. They are not a good choice for a community tank. Therefore, the ideal situation for the crayfish is a species tank.