Can Finger Fish and Popondetta Blue-eye Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 7, 2026
Not Recommended

Finger Fish and Popondetta Blue-eye are not recommended as tank mates due to incompatible water types. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

Finger Fish

Monodactylus argenteus

Popondetta Blue-eye

Pseudomugil connieae

🐠Family Group
Finger Fish
Oddballs
Popondetta Blue-eye
Rainbowfish
Temperament
Finger Fish
Semi-Aggressive (5/10)
Popondetta Blue-eye
Peaceful (1/10)
Temperature
✓ Compatible
Finger Fish
24–28°C
Popondetta Blue-eye
24–28°C
pH Range
✓ Compatible
Finger Fish
7.5–8.5
Popondetta Blue-eye
7.2–8
Hardness (dGH)
✓ Compatible
Finger Fish
12–30
Popondetta Blue-eye
8–15
Water Type
✗ No overlap
Finger Fish
Brackish Required
Popondetta Blue-eye
Freshwater Only
Flow Preference
✓ Compatible
Finger Fish
Moderate
Popondetta Blue-eye
Moderate
Min Tank Volume
Combined: 470 L
Finger Fish
470 L
Popondetta Blue-eye
55 L
Swimming Level
Shared: 1 zone
Finger Fish
Middle
Popondetta Blue-eye
TopMiddle
🏷️Behavior Tags
Finger Fish
Hyperactive / Fast SwimmerFin NipperPlant DestroyerAggressive to same species/look-alikes
Popondetta Blue-eye
Nano / Bite-sized (Predation Risk)Hyperactive / Fast SwimmerJumper (Lid Required)
Stocking calculator

Can your tank handle Finger Fish and Popondetta Blue-eye?

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.

Finger Fish
Popondetta Blue-eye
Test both in my tank

Behaviour & Temperament

Finger Fish is a moderately assertive species (5/10), while Popondetta Blue-eye is peaceful (1/10). This notable difference means Finger Fish may occasionally assert dominance over Popondetta Blue-eye.

Finger Fish and Popondetta Blue-eye 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: Popondetta Blue-eye is a known jumper, so a tight-fitting lid is essential.

Water Parameters

The safe temperature window for both species falls between 24°C and 28°C. Aim for the midpoint of this range (around 26.0°C) for optimal comfort.

Both fish can tolerate a pH between 7.5 and 8. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 12–15 dGH. Regular testing will ensure conditions stay within this range.

Crucially, these species require different water types — one needs freshwater while the other requires brackish conditions. This is a hard barrier to keeping them together.

Tank Setup

To house Finger Fish and Popondetta Blue-eye together, plan for an aquarium of at least 470 litres with a minimum length of 150 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: Smooth Gravel (Sensitive Barbels), Plants - Densely covered. Meeting these requirements will help both species thrive.

Note a potential conflict in setup requirements: Finger Fish is a plant destroyer, which conflicts with Popondetta Blue-eye's requirement for live plants. Compromise where possible or prioritise the more critical need.

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

Finger Fish and Popondetta Blue-eye 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 Finger Fish and Popondetta Blue-eye.

Frequently Asked Questions

Can Finger Fish and Popondetta Blue-eye live together?

No. This combination is not recommended. Key incompatibilities — such as different water type needs — make cohabitation unsafe.

What size tank do Finger Fish and Popondetta Blue-eye need?

A minimum of 470 litres (tank length at least 150 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 Finger Fish and Popondetta Blue-eye together?

Keep the aquarium between 24°C and 28°C. A target of around 26.0°C sits comfortably within both species' preferred ranges.

Are Finger Fish or Popondetta Blue-eye aggressive?

Finger Fish is moderately assertive (5/10) and Popondetta Blue-eye is peaceful (1/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.

What pH do Finger Fish and Popondetta Blue-eye need?

Both species overlap in the 7.5–8 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Will Finger Fish nip Popondetta Blue-eye's fins?

Finger Fish is a known fin nipper. If Popondetta Blue-eye has long or flowing fins, there is a real risk of fin damage. Keeping Finger Fish in a larger group can help redirect nipping behaviour toward conspecifics.

Editorial Review

Guidarium Editorial Desk

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

Last reviewed
May 7, 2026
Last updated
May 7, 2026
Issues or corrections?
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