Can Forktail Blue-eye and Freshwater Sole Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 6, 2026
Not Recommended

Forktail Blue-eye and Freshwater Sole are not recommended as tank mates due to piscivorous fish will prey on nano-sized tank mates.. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

Forktail Blue-eye

Pseudomugil furcatus

Freshwater Sole

Brachirus selheimi

🐠Family Group
Forktail Blue-eye
Rainbowfish
Freshwater Sole
Oddballs
Temperament
Forktail Blue-eye
Peaceful (2/10)
Freshwater Sole
Mostly Peaceful (4/10)
Temperature
✓ Compatible
Forktail Blue-eye
24–28°C
Freshwater Sole
22–28°C
pH Range
✓ Compatible
Forktail Blue-eye
7–8
Freshwater Sole
6.5–7.8
Hardness (dGH)
✓ Compatible
Forktail Blue-eye
5–15
Freshwater Sole
5–15
Water Type
✓ Compatible
Forktail Blue-eye
Freshwater Only
Freshwater Sole
Brackish Tolerant
Flow Preference
✓ Compatible
Forktail Blue-eye
Moderate
Freshwater Sole
Low
Min Tank Volume
Combined: 110 L
Forktail Blue-eye
55 L
Freshwater Sole
110 L
Swimming Level
✓ Different zones
Forktail Blue-eye
TopMiddle
Freshwater Sole
Bottom
🏷️Behavior Tags
Forktail Blue-eye
Nano / Bite-sized (Predation Risk)Hyperactive / Fast SwimmerJumper (Lid Required)
Freshwater Sole
Piscivore (Eats small/nano fish)Shrimp EaterFry PredatorDigger (Disturbs Substrate)Shy / Slow Moving (Easily Stressed)Nocturnal
Stocking calculator

Can your tank handle Forktail Blue-eye and Freshwater Sole?

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.

Forktail Blue-eye
Freshwater Sole
Test both in my tank

Behaviour & Temperament

Forktail Blue-eye is a peaceful species (2/10), while Freshwater Sole is generally mild-mannered (4/10). This modest difference means Freshwater Sole may occasionally assert dominance over Forktail Blue-eye.

In terms of spatial distribution, Forktail Blue-eye prefers the Top (Surface) and Middle (Open Water) zones, whereas Freshwater Sole occupies the Bottom (Substrate) zone. Because they use different levels of the water column, territorial disputes are less likely and the tank will appear more balanced.

There is a critical concern: the Nano / Bite-sized (Predation Risk) behaviour of one fish directly conflicts with the Piscivore (Eats small/nano fish) trait of the other — piscivorous fish will prey on nano-sized tank mates..

Additional behavioural considerations to keep in mind: Hyperactive swimmers can stress shy, slow-moving species through constant motion. Shrimp eaters may also prey on very small nano fish.

Worth noting: Freshwater Sole is nocturnal and will be most active after lights-out, naturally reducing daytime encounters. Also, Forktail 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 and 7.8. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 5–15 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Forktail Blue-eye and Freshwater Sole together, plan for an aquarium of at least 110 litres with a minimum length of 90 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: Plants - Densely covered, Sand (Sifters). 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

Forktail Blue-eye and Freshwater Sole 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 Forktail Blue-eye and Freshwater Sole.

Show 10 more tank sizes

Diet & Feeding

Feeding time deserves special attention with this pairing. Freshwater Sole is a known shrimp eater and may prey on small invertebrates or nano fish like Forktail Blue-eye.

Frequently Asked Questions

Can Forktail Blue-eye and Freshwater Sole live together?

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

What size tank do Forktail Blue-eye and Freshwater Sole need?

A minimum of 110 litres (tank length at least 90 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 Forktail Blue-eye and Freshwater Sole 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 Forktail Blue-eye or Freshwater Sole aggressive?

Forktail Blue-eye is peaceful (2/10) and Freshwater Sole is generally mild-mannered (4/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Forktail Blue-eye and Freshwater Sole need?

Both species overlap in the 7–7.8 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Does Freshwater Sole being nocturnal affect compatibility?

Freshwater Sole is most active after lights-out, which naturally reduces daytime encounters with its tank mate. This can actually be beneficial, as both fish get undisturbed time to feed and explore. Just ensure food reaches Freshwater Sole during evening hours.

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
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