The Galaxy Rasbora, also known as the Celestial Pearl Danio, is one of those tiny fish that really makes a big impression! With their dark blue-grey bodies, bright red and orange fins, and beautiful pearl-like spots, they look like little stars swimming through your aquarium.
They are peaceful, active and full of personality, making them a fantastic choice for planted, nano and community aquariums. They are also small enough to enjoy in aquariums from around 20 litres, provided the tank is well established and planted.
Here's a simple guide to keeping them happy and healthy:
Tank Size: Galaxy Rasboras can be kept in a well-planted aquarium from around 20 litres. A larger aquarium will give them more swimming space and make it easier to maintain stable water conditions.
Because they are social fish, we recommend keeping them in a group of at least 6, with a larger group being even better when space allows.
Substrate: Almost any aquarium-safe substrate will work. Fine sand, small gravel or a planted-tank substrate are all suitable.
Plants & Decorations: These little fish absolutely love planted aquariums! Dense plants give them places to hide and explore and help them feel secure.
Floating plants can also be a great addition. Just make sure you leave some open areas for swimming.
Galaxy Rasboras are fairly easy to care for once they are settled into a mature aquarium.
Temperature: 20–26°C
pH: 6.5–7.5
Hardness: Soft to moderately hard water is suitable.
Filtration: A gentle filter is ideal. Avoid very strong currents, as these are tiny fish and don't need powerful water movement.
Water Changes: A 20–30% water change once a week is a good routine. Aim for 0 ppm ammonia, 0 ppm nitrite, and keep nitrate preferably below 20–30 ppm.
As with most aquarium fish, keeping the water clean and stable is more important than chasing perfect numbers.
Galaxy Rasboras have tiny mouths, so their food needs to be small enough for them to eat comfortably.
Good options include:
Feed small amounts once or twice a day. Because they are so small, a little food goes a long way!
A varied diet will help keep them healthy and bring out their beautiful colours.
Galaxy Rasboras are peaceful community fish and can be kept with other small, peaceful species.
Suitable tankmates can include:
Avoid large, aggressive or particularly boisterous fish. Galaxy Rasboras are tiny and can easily become stressed or even become a meal for much larger fish.
Social Fish: Galaxy Rasboras are happiest in a group. We recommend keeping at least 6, although larger groups can be even more enjoyable to watch.
Peaceful: They are gentle little fish and won't cause problems for other peaceful tankmates.
Active & Curious: They spend their time exploring plants, swimming around the aquarium and investigating their surroundings.
A Little Shy: They may hide when first introduced to a new aquarium. Don't worry — give them some time and plenty of plants or other cover, and they will usually become much more confident.
Male Displays: Males may show off their colours and display to one another. This is completely normal behaviour and can be fascinating to watch.
Galaxy Rasboras are generally easy to keep when given clean, stable water and a suitable environment.
Like any aquarium fish, they can become more susceptible to illness if they are stressed or water quality is poor.
The best way to keep them healthy is simple:
Galaxy Rasboras can breed in a mature, well-planted aquarium.
They are egg scatterers, meaning females scatter their eggs among plants and other surfaces. The adults don't look after the eggs and may eat some of them.
If you'd like to raise the babies, dense plants, moss or spawning mops can provide places for the eggs and fry to hide.
The fry are extremely small when they hatch and need very small foods until they are large enough to accept regular fish food.
The Galaxy Rasbora / Celestial Pearl Danio is a brilliant little fish for planted and nano aquariums.
They are small, peaceful, colourful and full of personality, making them a great choice for both beginners and experienced fishkeepers. A well-planted aquarium from around 20 litres, a small group of these beautiful fish, good-quality food and regular water changes are all you need to give them a happy home.
Once they settle in, their colours really start to shine — and watching a group of Galaxy Rasboras weaving through a planted aquarium is something special!
The Galaxy Rasbora gets its nickname from its stunning appearance. Its dark body covered in tiny pearly spots looks remarkably like a miniature starry sky.
Despite being called the "Celestial Pearl Danio", this little fish was only discovered by science relatively recently, and its incredible appearance quickly made it a favourite among aquarium keepers around the world.
