How to take care of Cardinalfish?

We will talk about cardinalfish care in this blog post.We will also discuss important factors such as their habitat, types,lifespan,tank set-up, water parameters and healthcare, etc.Everything you need to know about cardinalfish care will be briefly discussed.


In this blog 

  • Key specifications of cardinalfish
  • Why is cardinalfish care important?
  • How many cardinalfish should you start with as a newcomer?
  • Habitat of cardinalfish
  • Types of cardinalfish
  • Different strains or colors of cardinalfish
  • General and physical attributes of cardinalfish
  • Cardinalfish lifespan
  • Cardinalfish tank set-up
  • Cardinalfish diet and feeding requirements
  • Cardinalfish healthcare and health conditions
  • Cardinalfish daily care and Bi-weekly care tips
  • Summary

How to take care of Cardinalfish?

Daily care tips for cardinalfish

  • Feed a vitamin enriched diet.
  • Feed them 2-3 times a day.
  • Defrost frozen food before feeding them.
  • Don’t overfeed
  • Always remove uneaten food from the tanks to avoid ammonia spikes in the tanks.
  • Check all the aquarium equipment to know if they are in working condition or not.
  • Maintain the temperature,pH,specific-gravity to keep them healthy.
  • If you find cardinals fighting with each other or get aggressive with each other then separate them immediately in a different tank. 

Bi-weekly care tips  for cardinalfish

  • Water quality should be maintained by changing tank water once a week.
  • 10-25% of water should be changed every 2-4 weeks.
  • If you are giving them live food daily or weekly once it is advised to quarantine it for weeks before feeding them. 
  • New individuals should be quarantined at least for 2 weeks before introducing them in the tank to avoid infections.
  • Tank filters, tank plants,and decors should be cleaned weekly to avoid the growth of unwanted bacteria in the tank.

Key specifications of Cardinalfish

Scientific name Pterapogon kauderni
Conservation status
Tropical marine fish (shallow habitat)Restricted to Indonesia (banggai island)Endangered
Lifespan5 years or longer
Body sizeBody shapeColorSexual dimorphism2-5 inches longMostly roundedBlack, white,silverMales larger than females(it can be determined only during breeding)
Another namesKaudern’s cardinal fishBanggai cardinalfishLongfin cardinalfish
Optimum temperatureOptimum pHWater hardnessSpecific gravity72F-82F8.1-8.48-12 dkH1.020-1.025
TemperamentBeginner or experienced Peaceful to semi-aggressiveIdeal beginner fish
Care levelEasy
Tank size and set-upTank type (Prefered)30 gallons (minimum)Community Reef tank
Preferred plants/decorationsOverhangs, nooks, live plants
CompatibilityOther Peaceful fish
Number of cardinalfish species found 200 species
BreedingCaptive breedingMales are mouth brooders (parental care)

Why is cardinalfish care important?

Cardinalfish are a very popular and a beautiful addition to your aquarium.They are now endangered (IUCN) due to human exploitation, mainly habitat destruction and illegal pet trade.

They are a bit expensive and are produced through captive breeding.So It’s very important to care for these beautiful fish very well by providing all the necessary conditions required for them to thrive in the home aquariums.

How many cardinalfish should you start with as a newcomer?

They are gregarious fish, so as a newcomer get them in pairs of 2 or 3 or as you wish.Get cardinals of the same size and add them simultaneously in the aquarium.

They do well in smaller groups or schools of 3-4 in a spacious tank.They are ideal aquarium fish for newcomers.I would suggest you get a pair of banngai cardindalfish that have already been paired up in pet shops.

They will not show aggression towards each other and it will be easier for them to acclimatize together in their new home.

If you are getting pajama cardinalfish then get them in groups of at least 6, because they are schooling fish and enjoy shoaling together in the aquarium.

Habitat of cardinalfish

Cardinals are saltwater marine fish and have a very limited geographical distribution.They are found in tropical and subtropical waters and are restricted to banggai island,indonesia.

They swim under shallow water, mainly the reef areas where the water movement is a bit slow and subdued lighting.

Types of cardinalfish

These are commonly sold cardinalfish for your aquariums.Have proper information before buying them,whether they are wild-caught or produced through captive breeding.

  • Pajama cardinalfish also known as spotted cardinal fish.
  • Black and white banner cardinalfish (banggai)
  • Glass cardinalfish
  • Threadfin cardinalfish
  • Orbic cardinal

Different strains or colors of cardinalfish

Simple yet refined color scheme and markings.Overall they have shiny silver colouration with pearly white spots and black stripes on the dorsal, pelvic and caudal fins.

  • Brown
  • Black
  • Silver
  • Red
  • Yellow striped

General and physical attributes of cardinalfish

  • Cardinalfish are small tropical marine fish, 2-5 inches in length (average adult size)
  • Sexual dimorphism is only prominent during breeding time.Males cardinals are usually larger than females and have a broad oral cavity.Female cardinals have round bodies.
  • They have a large mouth,large eyes,large scales and two dorsal fins.

Cardinalfish lifespan

Lifespan of a cardinalfish can be 5 years or even longer, it totally depends on the individual and the amount of care they are giving their aquatic pets.They thrive well in suitable water conditions and stress free environments.

Cardinalfish tank set-up

Tank sizeLight intensitySubstrateWater parametersTemperatureTank plantsTank mates

Tank size for cardinalfish

  • House your cardinalfish in a 30 gallons tank.
  • Pajama cardinals can be kept in a 20 gallons tank and if you are keeping them in a group of 6 or 8 then get a bigger tank to keep them.
  • Kaudern’s cardinal fish needs a 125 gallons tank if you are keeping them in larger groups.
  • Cardinals occupy the middle region of the tanks.Provide them nice open space for swimming and lots of hiding spots to feel safe and secure.Don’t overcrowd the tank, it could stress them. 
  • Install proper filtration system in the tank, not the powerful one as they are slow swimmers.

Light intensity for cardinalfish

  • Cardinalfish Prefer- Low lightings
  • Cardinalfish are nocturnal species and prefer dim or low lighting in their aquarium.

Substrate/Decoration for cardinalfish

Cardinalfish don’t need a great substrate to thrive, since they are not bottom dwellers.

  • They are not bottom dwellers, and swim mainly in the middle or top regions of the tank, so bottom substrate is not an issue.You can choose any substrate of your choice.
  • Bare bottom with proper reef setting would be a great idea.It will replicate their original habitat.
  • Avoid sharp and edgy substrate as it can hurt your cardinalfish, although they won’t swim near the bottom but as a precautionary measure you can keep this in mind. 
  • Decors-Cardinalfish don’t need heavy decorations.Live rocks, crevices,overhangs,nooks,etc for hiding when they feel nervous and threatened

Water parameters for cardinalfish

Water parameters play a vital role in any fish aquarium.This decides how long your pet will survive in the artificial condition.

So,it’s extremely important to provide the right pH, water hardness, specific gravity and salinity in the aquariums.

Water conditions should be monitored from time to time and its replacement is equally important to avoid the ammonia pollution in the tank.The best solution is to mimic their original habitat.

  • Cardinalfish are slow swimmers so moderate water flow should be maintained in the tank.
  • Optimum pH- 8.1-8.4
  • Water hardness- 8-12 dkH
  • Specific gravity- 1.020-1.025
  • You can use proper water testing kits and pH kits to check the water conditions.

Temperature for cardinalfish

Temperature equally plays a vital role in the aquarium for their overall metabolism.

An ideal temperature between 72F-82F should be maintained in the cardinalfish tanks.

  • Optimum temperature- 72F-82F
  • A  thermometer can be used to adjust the exact temperature in the tank.

Tank plants for cardinalfish

All they need is some live plants, a great swimming area and hiding space where they can enjoy their time without any stress.

  • Live plants which go well with the reef tanks.

Tank mates for cardinalfish

Cardinalfish are mainly peaceful aquarium fish and get along well with other peaceful and methodical swimmers.They are slow swimmers and love to swim at their own pace around the tank.

They are not aggressive but they can  get aggressive in overcrowded tanks.

List of their favorite tank mates:

  • Gobies
  • Angelfish
  • Blennies
  • Clownfish
  • Groupers
  • Damselfish
  • Pseudochromis
  • Tangs
  • Wrasses

Reef type tank mates:

  • Snail
  • Shrimp
  • Sea anemones

Cardinalfish diet and feeding requirements

Feeding them is quite easy.They eat anything happily but i would suggest you to feed them vitamin enriched diets, as this can keep them healthy overall and their body colouration too.

It would be better to replicate what they prefer in the wild and try to provide them the same, if possible.They don’t eat regular pellets and flakes so get marine pellets for them which are available commercially.

List of some of their favorite food:

  • Feeder shrimps,Mysis shrimps
  • Bloodworms
  • Finely diced krills,cockles
  • Marine pellet
  • Live feeder fish

Cardinalfish healthcare and health conditions

Cardinalfish are usually disease resistant fish and are not prone to any specific disease, but they can get common saltwater fish disease in poorly maintained tanks.

Monitor water regularly and other vital parameters to know if they are getting any of the listed symptoms.Medications are available, kindly consult your vet before giving any kind of medications to them.

Some common ailments:

  • Fin rot
  • Marine ich
  • Iridovirus disease


  • Appetite loss
  • Loss of colouration
  • white spots on body and mouth
  • Difficulty in respiration
  • Weight loss
  • Cloudy eyes
  • Irregular swimming pattern
  • Frayed fins


Cardinalfish are pretty,silent,shy and peaceful saltwater aquarium fish.They are slow swimmers and get along well with tank mates of similar temperaments and habits. 

Larger tanks with a good amount of live rocks meticulously arranged and plenty of caves overhangs, crevices,open swimming areas and hiding spaces will give them the exact touch of their natural habitats.

They are not hyper-active,so If you’re looking for a hyperactive species then definitely it’s not the one.They are indeed a great beginner fish and their care is a piece of cake.

Don’t buy wild caught cardinal banggai for your aquariums,instead go for captive raised ones because they are more suitable for the home aquariums and can adapt easily in that environment.

Frequently asked questions on cardinalfish care

Are cardinal fish easily available in pet shops??

Vast majority of banngai cardinafish in the market is illegal. One should know how these fish are being exported from the wild to the aquarist before buying them.Use your purchasing power and support sustainable aquarium trade.

Can we feed prepared food to cardinalfish?

Yes, cardinalfish can be trained to eat prepared foods.You just have to maintain the feeding time table and feeding frequency properly.

Are Banggai cardinalfish aggressive?

Yes, banggai cardinal fish are aggressive fish and should be either kept alone or in pairs to avoid fights in aquariums.