Can Celestial Pearl Danio (Galaxy Rasbora) and Masked Julie (Julidochromis) Live Together?

🔴Not Recommended

Celestial Pearl Danio (Galaxy Rasbora) and Masked Julie (Julidochromis) are not recommended as tank mates due to conflicting pH requirements. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

Celestial Pearl Danio (Galaxy Rasbora)

Danio margaritatus

Masked Julie (Julidochromis)

Julidochromis transcriptus

🐠Family Group
Celestial Pearl Danio (Galaxy Rasbora)
Cyprinids
Masked Julie (Julidochromis)
Cichlids - African
Temperament
Celestial Pearl Danio (Galaxy Rasbora)
Peaceful (2/10)
Masked Julie (Julidochromis)
Semi-Aggressive (6/10)
Temperature
✓ Compatible
Celestial Pearl Danio (Galaxy Rasbora)
20–26°C
Masked Julie (Julidochromis)
23–27°C
pH Range
✗ No overlap
Celestial Pearl Danio (Galaxy Rasbora)
6.5–7.5
Masked Julie (Julidochromis)
8–9
Hardness (dGH)
✓ Compatible
Celestial Pearl Danio (Galaxy Rasbora)
5–15
Masked Julie (Julidochromis)
10–20
Water Type
✓ Compatible
Celestial Pearl Danio (Galaxy Rasbora)
Freshwater Only
Masked Julie (Julidochromis)
Freshwater Only
Flow Preference
✓ Compatible
Celestial Pearl Danio (Galaxy Rasbora)
Low
Masked Julie (Julidochromis)
Moderate
Min Tank Volume
Combined: 72 L
Celestial Pearl Danio (Galaxy Rasbora)
38 L
Masked Julie (Julidochromis)
60 L
Swimming Level
Shared: 2 zones
Celestial Pearl Danio (Galaxy Rasbora)
MiddleBottom
Masked Julie (Julidochromis)
BottomMiddle
🏷️Behavior Tags
Celestial Pearl Danio (Galaxy Rasbora)
Nano / Bite-sized (Predation Risk)Shy / Slow Moving (Easily Stressed)
Masked Julie (Julidochromis)
Territorial (Defends specific area)Aggressive to same species/look-alikesFry PredatorShy / Slow Moving (Easily Stressed)

Behaviour & Temperament

Celestial Pearl Danio (Galaxy Rasbora) is a peaceful species (2/10), while Masked Julie (Julidochromis) is moderately assertive (6/10). This notable difference means Masked Julie (Julidochromis) may occasionally assert dominance over Celestial Pearl Danio (Galaxy Rasbora).

Celestial Pearl Danio (Galaxy Rasbora) and Masked Julie (Julidochromis) both frequent the Middle (Open Water) and Bottom (Substrate) region of the setup. This overlap can increase competition for space, so providing ample room and cover is important to keep both species comfortable.

Water Parameters

The safe temperature window for both species falls between 23°C and 26°C. Aim for the midpoint of this range (around 24.5°C) for optimal comfort.

The pH requirements of Celestial Pearl Danio (Galaxy Rasbora) (6.5–7.5) and Masked Julie (Julidochromis) (8–9) do not overlap, making it impossible to satisfy both species simultaneously.

For general hardness, the shared comfort zone is 10–15 dGH. Regular testing will ensure conditions stay within this range. An aquarium test kit is recommended for monitoring.

Tank Setup

To house Celestial Pearl Danio (Galaxy Rasbora) and Masked Julie (Julidochromis) together, plan for an aquarium of at least 72 litres with a minimum length of 60 cm. This accounts for the larger species' space requirements with an additional 20 % buffer to reduce territorial tension.

Providing a mix of open swimming space and sheltered areas with rocks, driftwood, or plants will keep both species comfortable and allow natural behaviour.

Specific environmental needs for this combination include: Plants - Densely covered, Sand (Sifters). Meeting these requirements will help both species thrive.

Both species do well with low (still water) water movement, so a standard filtration setup rated for the tank volume should suffice.

Find the right tank equipment

Browse tanks, décor, and equipment suited for this setup.

Frequently Asked Questions

Can Celestial Pearl Danio (Galaxy Rasbora) and Masked Julie (Julidochromis) live together?

No. This combination is not recommended. Key incompatibilities — such as critical behavioural conflicts — make cohabitation unsafe.

What size tank do Celestial Pearl Danio (Galaxy Rasbora) and Masked Julie (Julidochromis) need?

A minimum of 72 litres (tank length at least 60 cm) is recommended. This provides enough space for both species to establish their own areas and reduces the likelihood of territorial disputes.

What water temperature is best for Celestial Pearl Danio (Galaxy Rasbora) and Masked Julie (Julidochromis) together?

Keep the aquarium between 23°C and 26°C. A target of around 24.5°C sits comfortably within both species' preferred ranges.

Are Celestial Pearl Danio (Galaxy Rasbora) or Masked Julie (Julidochromis) aggressive?

Celestial Pearl Danio (Galaxy Rasbora) is peaceful (2/10) and Masked Julie (Julidochromis) is moderately assertive (6/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.

What pH do Celestial Pearl Danio (Galaxy Rasbora) and Masked Julie (Julidochromis) need?

Their pH requirements do not overlap. Celestial Pearl Danio (Galaxy Rasbora) prefers 6.5–7.5, while Masked Julie (Julidochromis) needs 8–9. This makes them incompatible in the same water chemistry.

How do I manage Masked Julie (Julidochromis)'s territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Masked Julie (Julidochromis) space to claim a territory without encroaching on the other fish's area. Adding décor that divides the tank into distinct zones works especially well.


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