Can Marlier's Julie and Neon Green Rasbora (Kubotai) Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 6, 2026
Not Recommended

Marlier's Julie and Neon Green Rasbora (Kubotai) 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

Marlier's Julie

Julidochromis marlieri

Neon Green Rasbora (Kubotai)

Microdevario kubotai

🐠Family Group
Marlier's Julie
Cichlids - African
Neon Green Rasbora (Kubotai)
Cyprinids
Temperament
Marlier's Julie
Semi-Aggressive (6/10)
Neon Green Rasbora (Kubotai)
Peaceful (1/10)
Temperature
✓ Compatible
Marlier's Julie
23–27°C
Neon Green Rasbora (Kubotai)
20–27°C
pH Range
✗ No overlap
Marlier's Julie
8.2–9.3
Neon Green Rasbora (Kubotai)
6–7.5
Hardness (dGH)
✓ Compatible
Marlier's Julie
10–25
Neon Green Rasbora (Kubotai)
2–10
Water Type
✓ Compatible
Marlier's Julie
Freshwater Only
Neon Green Rasbora (Kubotai)
Freshwater Only
Flow Preference
✓ Compatible
Marlier's Julie
Moderate
Neon Green Rasbora (Kubotai)
Moderate
Min Tank Volume
Combined: 114 L
Marlier's Julie
114 L
Neon Green Rasbora (Kubotai)
38 L
Swimming Level
Shared: 1 zone
Marlier's Julie
BottomMiddle
Neon Green Rasbora (Kubotai)
TopMiddle
🏷️Behavior Tags
Marlier's Julie
Territorial (Defends specific area)Aggressive to same species/look-alikesDigger (Disturbs Substrate)Fry Predator
Neon Green Rasbora (Kubotai)
Nano / Bite-sized (Predation Risk)Hyperactive / Fast SwimmerJumper (Lid Required)
Stocking calculator

Can your tank handle Marlier's Julie and Neon Green Rasbora (Kubotai)?

Compatibility is only part of the answer. Test both fish with your real tank size, current stock, and maintenance needs to see if you have enough space and a safe stocking level before you add them.

Marlier's Julie
Neon Green Rasbora (Kubotai)
Test both in my tank

Behaviour & Temperament

Marlier's Julie is a moderately assertive species (6/10), while Neon Green Rasbora (Kubotai) is peaceful (1/10). This notable difference means Marlier's Julie may occasionally assert dominance over Neon Green Rasbora (Kubotai).

Marlier's Julie and Neon Green Rasbora (Kubotai) both frequent the Middle (Open Water) region of the setup. This overlap can increase competition for space, so providing ample room and cover is important to keep both species comfortable.

Worth noting: Neon Green Rasbora (Kubotai) is a known jumper, so a tight-fitting lid is essential.

Water Parameters

The safe temperature window for both species falls between 23°C and 27°C. Aim for the midpoint of this range (around 25.0°C) for optimal comfort.

The pH requirements of Marlier's Julie (8.2–9.3) and Neon Green Rasbora (Kubotai) (6–7.5) do not overlap, making it impossible to satisfy both species simultaneously.

For general hardness, the shared comfort zone is 10–10 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Marlier's Julie and Neon Green Rasbora (Kubotai) together, plan for an aquarium of at least 114 litres with a minimum length of 80 cm. This recommendation combines the stricter species minimums with a community-load allowance so the pairing has realistic long-term space and filtration headroom.

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: Sand (Sifters), Plants - Densely covered, Plants - lighly covered, Leaf Litter/Blackwater. Meeting these requirements will help both species thrive.

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

Why This Pairing Usually Fails in Practice

Marlier's Julie and Neon Green Rasbora (Kubotai) are the kind of pair that can look acceptable in a shop but become a maintenance problem at home. The main risk is not a single number in the chart; it is the way incompatible behavior, water needs, or pressure on space compounds over time once both fish are established in the same tank.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Marlier's Julie and Neon Green Rasbora (Kubotai).

Show 11 more tank sizes

Frequently Asked Questions

Can Marlier's Julie and Neon Green Rasbora (Kubotai) live together?

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

What size tank do Marlier's Julie and Neon Green Rasbora (Kubotai) need?

A minimum of 114 litres (tank length at least 80 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 Marlier's Julie and Neon Green Rasbora (Kubotai) together?

Keep the aquarium between 23°C and 27°C. A target of around 25.0°C sits comfortably within both species' preferred ranges.

Are Marlier's Julie or Neon Green Rasbora (Kubotai) aggressive?

Marlier's Julie is moderately assertive (6/10) and Neon Green Rasbora (Kubotai) is peaceful (1/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.

What pH do Marlier's Julie and Neon Green Rasbora (Kubotai) need?

Their pH requirements do not overlap. Marlier's Julie prefers 8.2–9.3, while Neon Green Rasbora (Kubotai) needs 6–7.5. This makes them incompatible in the same water chemistry.

How do I manage Marlier's Julie's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Marlier's Julie 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.

Editorial Review

Guidarium Editorial Desk

Reviewed against Guidarium care, stocking, and compatibility standards. Read the editorial policy.

Last reviewed
May 6, 2026
Last updated
May 6, 2026
Issues or corrections?
Contact the editorial team

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