Celestial Pearl Danio Care Guide: Tank Size, Diet, Shrimp Compatibility & Tank Mates

Celestial Pearl Danios (Danio margaritatus), also called Galaxy Rasboras, are peaceful nano fish known for their pearl-like white spots, dark blue-black bodies, and red-orange fins. They stay under 1 inch, do best in a proper social group, and are especially well suited to mature planted aquariums.

At Razz Aquatics, we keep the guidance for this species simple: stable water, appropriately small food, plenty of plant cover, and a group large enough for natural social behavior. Product-page care information should always take priority over generic nano-fish advice.

By Razz Aquatics
Published September 17, 2026
Updated September 17, 2026

Celestial Pearl Danio Care at a Glance

What Is a Celestial Pearl Danio?

Celestial Pearl Danios are small freshwater fish from Myanmar that became popular in the aquarium hobby for their distinctive spotted pattern and compact adult size. They are often sold under the older common name Galaxy Rasbora, but both names refer to the same species, Danio margaritatus.

They are best thought of as a peaceful social nano fish rather than a fish to keep singly or in a tiny decorative tank. Group size, swimming space, plant cover, food size, and stable water all affect how confidently they behave.

Keep a Proper-Sized Group

Razz Aquatics recommends keeping at least 10 Celestial Pearl Danios. In our experience, larger groups are generally more active, less shy, and show stronger coloration and more natural social behavior than very small groups.

A 10-gallon aquarium is our minimum recommendation. A 20-gallon long is an excellent choice for a larger group because the extra horizontal swimming space allows fish to spread out while still staying within sight of one another.

Do not use a simple fish-per-gallon formula. Tank footprint, filtration, plant mass, water quality, and the number of tank mates all matter.

Set Up the Aquarium Before the Fish Arrive

Celestial Pearl Danios should go into a fully cycled aquarium. Ammonia and nitrite should both test at 0 ppm before stocking. The biological filter should already be established and the aquarium should be stable rather than newly filled.

A gentle sponge filter can work well for this species. Hang-on-back and canister filters can also work when the flow is moderate and fish are not being pushed around the aquarium.

Read the Razz Aquatics Nano Fish Care Guide for broader guidance on cycling, filtration, and choosing a tank footprint.

Plants, Cover and Swimming Space

Celestial Pearl Danios are especially well suited to planted aquariums. Dense plants and moss provide cover, reduce visual stress, and help break up sightlines between displaying males.

Useful choices include mosses, Anubias, Java fern, and stem plants that suit the aquarium's light and maintenance routine. Leave open mid-water swimming space instead of filling the entire aquarium with dense growth.

Darker substrate can make their pattern and fin color stand out visually, but substrate color is secondary to water quality and proper habitat structure.

Browse Razz Aquatics aquarium plants and mosses when planning a planted CPD setup.

Water Parameters

A practical target range for Celestial Pearl Danios is 73–79°F with a pH of 6.5–7.5. Stable conditions matter more than repeatedly adjusting the aquarium to chase one exact number.

Before adding fish, confirm:

• Ammonia: 0 ppm
• Nitrite: 0 ppm
• Temperature is stable
• pH is within the suitable range
• Replacement water is dechlorinated and reasonably matched to the aquarium

Avoid abrupt temperature or chemistry changes during maintenance.

What Do Celestial Pearl Danios Eat?

Their mouths are small, so food size matters. Oversized pellets may be ignored even when the fish are hungry.

At Razz Aquatics, we feed appropriately small foods such as:

• Micro pellets
• Finely crushed quality flake
• Baby brine shrimp
• Micro worms
• Other nano-sized frozen or live foods

Feed small portions once or twice daily and watch whether the entire group is getting food. Remove the assumption that food reaching the tank means every fish has eaten.

Are Celestial Pearl Danios Safe With Shrimp?

They are generally compatible with adult Neocaridina and Caridina shrimp. Adult shrimp are unlikely prey for a fish this small, but newly hatched shrimplets may still be eaten if caught.

Dense moss and fine-leaved plants give shrimplets more places to hide. If maximizing shrimp reproduction is the main goal, a shrimp-only aquarium remains the safer option.

Choosing Tank Mates

Good tank mates are peaceful species that share compatible water and do not outcompete Celestial Pearl Danios at feeding time.

Possible companions include:

• Ember Tetras
• Chili Rasboras
• Pygmy Corydoras
• Otocinclus
• Other small, peaceful community fish with compatible requirements

Avoid aggressive fish, persistent fin-nippers, and species large enough to swallow them. Compatibility is based on the exact species and aquarium, not just whether a fish is labeled “community.”

Arrival and Acclimation

Have the aquarium fully prepared before the shipment arrives. Dim the lights, inspect the fish, and acclimate them gradually rather than making abrupt changes.

Use the Razz Aquatics livestock acclimation guide for the complete process. When practical, transfer fish without adding shipping water to the aquarium.

Reduced color or some hiding can occur after shipping, but test water and observe closely if the fish continue to act unusually.

Common Problems

Celestial Pearl Danios are hiding

New fish may hide while settling in. Check group size, cover, lighting, tank mates, and water quality. Persistent hiding may indicate stress, bullying, unsuitable conditions, or illness.

They are not eating

Confirm that the food is small enough. Offer familiar micro foods and watch for competition. Test water if appetite remains poor.

Color looks pale

Shipping stress, a small social group, bright surroundings, poor diet, or water-quality problems can all affect appearance. Give new arrivals time to settle and correct any husbandry issue before assuming color loss is permanent.

Celestial Pearl Danio Care Checklist

• Use a fully cycled aquarium.
• Keep at least 10 CPDs.
• Provide a 10-gallon or larger tank with useful horizontal space.
• Keep temperature around 73–79°F and pH around 6.5–7.5.
• Provide plants, cover, and open swimming space.
• Feed appropriately small foods.
• Choose peaceful tank mates with compatible requirements.
• Expect some risk to newly hatched shrimp.
• Acclimate gradually and avoid adding shipping water when practical.

Frequently Asked Questions

How many Celestial Pearl Danios should I keep?

Razz Aquatics recommends at least 10. Larger groups are generally more active and confident when the aquarium has enough space and filtration.

Can Celestial Pearl Danios live in a 10-gallon tank?

Yes. A 10-gallon is our minimum recommendation for a proper group. A 20-gallon long provides more swimming room and makes it easier to keep a larger school.

Are Celestial Pearl Danios beginner friendly?

Yes, when the aquarium is mature, fully cycled, and stable. Their main needs are appropriate food size, a proper social group, and peaceful tank mates.

Are Celestial Pearl Danios safe with shrimp?

They are generally safe with adult shrimp, but very small shrimplets may be eaten. Dense planting can reduce the risk.

What do Celestial Pearl Danios eat?

Feed small foods such as micro pellets, finely crushed flake, baby brine shrimp, micro worms, and other nano-sized foods.

Do Celestial Pearl Danios need a planted tank?

A planted tank is strongly recommended because plants provide cover and sight breaks. They can be kept without heavy planting, but the aquarium should still provide security and stable conditions.

Shop Celestial Pearl Danios

Razz Aquatics sells quarantined Celestial Pearl Danios / Galaxy Rasboras in groups of 3, 6, 9, and 12. Fish are observed at our Iowa facility before shipment and ship Monday through Wednesday via Overnight / Next Day Air with our Live Arrival Guarantee.

Questions before ordering? Contact Razz Aquatics and we will help you plan the right setup.