Can Crabs Live with Betta Fish? Complete Compatibility Guide

Hey, fellow fishkeeper! Betta fish and crabs make interesting pets as they are both known for their unique quirky looks, but can crabs live with betta fish in the same tank, or should they be kept apart at all costs?

Some sources claim that you can put crabs with betta fish in a freshwater aquarium, while others suggest that it might not be in their best interest to be kept together. 

I’ll go over the requirements of these wonderful creatures so we can establish if they will get along blissfully or not.

Can Crabs and Betta Fish Coexist Happily?

Can Crabs Live With Betta Fish

There are a few things to consider when establishing whether can crabs live with betta fish in the same tank successfully or not.

  • Temperament
  • Tank Setup
  • Water Parameters
  • Diet
  • Tankmates


Betta Fish Temperament

Betta fish don’t have the nickname Siamese fighting fish for no reason! Having said that the majority that I have kept have been pretty laid back, you do get the occasional feisty one though!

Betta fish can be very territorial and may not tolerate sharing their home with any crabs, if you choose smaller crabs they may harass or even eat them.

If your betta is feisty, do not risk adding any crabs or other tank mates in with them, as it won’t end well for one of them.

Crabs Temperament

This varies for each type of crab, some crabs are peaceful and won’t bother tankmates unless they feel threatened, while others are more aggressive and territorial and your betta fish could end up getting seriously injured or worse.

Two of the most peaceful fully aquatic freshwater crabs are:

  • Pom Pom Crabs
  • Thai Micro Crabs

The downside to these crabs is they are both small (Thai 0.5 inches, Pom Pom 1 inch), so a betta fish may harass or even try to eat them, but if you choose a larger crab, like the Panther crab (4 inches), they are more aggressive and have larger claws, so can inflict more harm to your betta.

Finding a good balance of size and temperament for these two species to happily coexist is difficult as there’s always a risk that one will harm the other.

Tank Requirements and Setup

Carb & Betta Fish Tank Size

Creating an ideal tank setup is vital for keeping happy and thriving pets, and this is where it gets a bit tricky if you want to house betta fish and crabs together as they require different setups.

A lot of crabs are semi-aquatic or even land-based and need to live in a paludarium (An enclosure that incorporates both terrestrial and aquatic elements). 

Tank Size and Decor

A 20-gallon aquarium is a suitable size for housing a betta with tank mates, this allows them to have their own space and helps to avoid conflict.

Betta fish enjoy a planted tank, choose some live plants with broad leaves (Anubias are a great choice), as it gives them a place to rest, I imagine it’s hard work swimming all day with those long fins! Be sure to avoid adding any toxic plants.

Ensure any decorations have sharp edges filed down to help avoid injury.

Crabs require a soft, sandy substrate, that allows them to dig, burrow and scavenge for any leftover food at the bottom of the tank.

Add live plants that provide good ground coverage, Christmas moss is a great choice as it gives crabs somewhere to hide.

Additionally, adding places to hide such as caves, rock formations, and driftwood can create a more natural and comfortable environment for them to explore. 

Some crabs are skilled climbers and will try to escape given half a chance, so having a lid is essential.

Water Quality and Parameters

Crab & Betta Fish Water Conditions

Having good water quality and the correct parameters is essential if you want your betta fish and crabs to be healthy. However, this is where the main issues arise as they have a different set of optimum requirements.

Betta fish prefer the water to be warmer and on the softer side, whereas crabs tend to prefer the water to be cooler and harder, with higher calcium levels to help keep their shell healthy.

Ideal Temperature & pH For Betta Fish

Being tropical fish, bettas like the water to be kept warm at a temperature of 78°-82°F (25.5°-27.5°C) and on the softer side, with a pH of 6.0-7.0.

Use a heater to maintain the appropriate water temperature. I use Fluval heaters and recommend the Fluval E100 for a 20 gallon tank due to its high build quality, accuracy, and reliability.

Fluval E100 Heater

Ideal Temperature & pH For Freshwater Crabs

Crabs on the other hand tend to prefer the water a little cooler (depending on the species).

Thai micro crabs are the closest in compatibility of temperature as they come from the same region and like the water to be around 72°-82°F (22°-27.5°C), with a pH of around 6.5-8.0.

Pom Pom crabs prefer the water a little cooler at around 68°-78°F (20°-25°C) with a pH of 6.5-7.2.

To keep a crabs exoskeleton healthy they need a higher calcium level in the water, so it’s essential you test the water and supplement with calcium, such as cuttlebone if needed.

Water Quality & Filtration

Testing the water using strips to ensure nitrate levels are safe and cleaning your tank on a regular basis is the best way to ensure your aquatic pets stay healthy.

API 5 in 1 Test Strips
Pawfly Aquarium Bio Sponge Filter

Filtration is needed to keep tanks’ clean, oxygenated and provide somewhere for beneficial bacteria to colonize, keeping your tank’s nitrogen cycle in check, thus keeping the water safe between changes.

It’s important to have a gentle flow rate for betta fish, as they can get pushed around in the current if it’s too strong. A sponge filter or canister filter with an adjustable flow rate are the best options.

Diet and Feeding

Crab & Betta Fish Diets

Bettas and crabs have different dietary requirements, which makes feeding in a shared environment a little challenging. Bettas are carnivores and rely on a diet high in protein. 

On the other hand, crabs are omnivores, which means they consume both plant and animal matter. Their diet comprises algae, dead plant material, small insects, and small fish species, depending on the type of crab.

Feeding Betta Fish

I’ve found that providing a varied diet for my Betta fish is essential to ensure he gets all the necessary nutrients and helps to keep his colors lovely and bright.

Some of the best foods for bettas include pellets specifically designed for them, as these contain the ideal combination of proteins, vitamins, and minerals for these carnivorous fish. 

Keep in mind that not all Betta pellets are created equal. I always look for high-quality pellets with a good balance of protein and other nutrients.

In addition to pellets, I like to offer my Betta the occasional treat of live or frozen foods, such as brine shrimp, bloodworms, or daphnia, being carnivores your betta will eagerly gobble these up, Bert (my betta) cannot get enough of the Ultra Fresh Shrimp Patties – he loves them!

These types of food closely resemble their natural diet and can help to enhance their color and overall health.

When feeding my Betta, I offer a small amount of food, enough for him to consume within a couple of minutes, once or twice a day.

It’s essential not to overfeed, as this can cause health problems and lead to poor water quality in the aquarium.

Skipping feeding your betta fish for a day or 2 won’t cause it any harm, in fact, it can be beneficial.

Feeding Freshwater Crabs

It’s important to make sure any food you feed to your crabs sinks down to them, as it can get gobbled up by other greedy fish before it reaches them.

Crabs are scavengers and will eat most things, dead plant matter, small fish, shrimps, snails, leftover food particles, detritus, and algae.

Provide a variety of foods including:

Choosing Tank Mates

Successfully putting together a diverse and harmonious aquarium community is super rewarding and great to look at.

But, as we’ve established, bettas and crabs are not the best choice as tank mates and there are much better options to choose from, which I’ll go over now.

Suitable Betta Fish Tank Mates

Suitable Betta Fish Tank Mates

Choose peaceful community fish that prefer to hang out in a different area of the tank and that won’t nip at the betta’s delicate fins and importantly, require similar tank conditions.

Here are a few suitable choices:

  • Bristlenose Pleco
  • Clown Pleco
  • Corydoras
  • Kuhli Loach
  • Lambchop Rasboras
  • Pygmy Corydoras
  • Mystery Snail
  • Neon, Ember, Emerald, Gold or Rummynose Tetras
  • Nerite Snail
  • Otocinclus Catfish

Suitable Crab Tank Mates

Suitable Crab Tank Mates

This varies greatly depending on the type of crab, so I’ll go over some popular fully aquatic freshwater species and put some suitable tank buddies.

Suitable Micro Thai Crab Tankmates

Also known as the false spider crap, they are peaceful, tiny (0.5 inch) crabs that will tolerate small peaceful fish to live alongside them.

  • Ember Tetra
  • Harlequin Rasboras
  • Kuhli Loaches
  • Neon Tetra
  • Nerite Snails
  • Other Micro Thai Crabs
  • Pygmy Corydoras
  • Rummynose Tetras
  • Shrimps

Suitable Pom Pom Crab Tank Mates

Pom Pom crabs are a bit bigger (1 inch fully grown) and may eat tiny fish given the opportunity.

  • Cherry Barbs
  • Cory Catfish
  • Ember Tetra
  • Harlequin Rasboras
  • Platies
  • Rummynose Tetras

Suitable Panther Crab Tank Mates – None!

I wouldn’t risk adding fish in with Panther crabs as they can reach up to 4 inches when fully grown.

They are opportunistic feeders and will make a snack out of anything they can get their claws on, for this reason, I recommend they live alone.

If you decide to add some fish, choose larger ones that stay towards the top of the tank, out of the way of those claws.

Risks and Precautions

Taking all these factors into consideration, it’s clear that keeping bettas and crabs together in the same tank requires some caution.

Providing ample space and hiding spots for both species and monitoring their behavior closely can help to minimize potential risks. 

Consider whether it’s worth the risk of housing these two creatures together, I personally wouldn’t risk it as there are much more suitable tank mates for them both.

Frequently Asked Questions


Can Hermit Crabs Live With Betta Fish?

Hermit crabs are super cool little creatures, but unfortunately, they are not a suitable tankmate for betta fish.

Hermit crabs spend most of their time on land. They require a deep sand substrate, access to water, and high humidity levels.

Can Red Claw Crabs Live With Betta Fish?

No red claw crabs can not live with betta fish as they require brackish water (slightly salty) to live in and betta fish live in freshwater.

Can Fiddler Crabs Live With Betta Fish?

No fiddler crabs can not live with betta fish, they need to live in a slightly brackish paludarium with a deep sand substrate to allow them to burrow.

What Types Of Crabs Are Compatible With Bettas?

No type of crab is ideal to live with a betta as we established above.

Some people have managed to successfully keep them together, but you have to compromise the ideal water conditions for one of them.

Can Bettas Live With Other Fish Species?

Yes, Bettas can live with other species (with caution), but they are perfectly happy living on their own.

I’ve listed some freshwater fish above that can live with a betta.

What Size Tank Is Ideal For Bettas and Their Compatible Tank Mates?

If you want to keep a betta with a few other compatible fish, you’ll need a 20-gallon tank due to bettas’ having a semi-aggressive nature.

This allows the fish to each have their own space within the tank, thus helping avoid any conflict.

Final Thoughts On Can Crabs Live With Betta Fish Happily….

The compatibility of different species is a crucial factor to consider if you want them to live happily.

When it comes to bettas and crabs, these two creatures have unique needs and behaviors that must be taken into account and after looking at their individual needs we can see they are not an ideal combination when we take in all the factors above.

If you’re really set on having a betta fish live with crabs, I’d choose a female betta as they are generally a bit more laid back than males and they have shorter fins, so there’s less opportunity for the crab to nip at the fins.

Check out the freshwater section for more compatibility guides, and the aquarium health section for guides and tips to keep your aquarium in tip-top shape.



Hey, fellow fish enthusiast 👋! I'm Paul and I've been an aquarium addict since I won my first goldfish at the fair many years ago. Let me share with you the knowledge that I've gained along the way (and avoid the mistakes I've made!), so you too can create an underwater paradise for your aquatic friends.