Can Florida Flagfish and Freshwater Sole Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 6, 2026
Possible with Caution

Keeping Florida Flagfish and Freshwater Sole together is possible but requires caution due to potential behavioral clashes. Provide a spacious tank of at least 110 litres with plenty of hiding spots to reduce stress. Monitor behaviour closely, especially during the first few weeks.


At a Glance

Florida Flagfish

Jordanella floridae

Freshwater Sole

Brachirus selheimi

🐠Family Group
Florida Flagfish
Killifish
Freshwater Sole
Oddballs
Temperament
Florida Flagfish
Semi-Aggressive (5/10)
Freshwater Sole
Mostly Peaceful (4/10)
Temperature
✓ Compatible
Florida Flagfish
18–26°C
Freshwater Sole
22–28°C
pH Range
✓ Compatible
Florida Flagfish
6.5–8.5
Freshwater Sole
6.5–7.8
Hardness (dGH)
✓ Compatible
Florida Flagfish
10–25
Freshwater Sole
5–15
Water Type
✓ Compatible
Florida Flagfish
Brackish Tolerant
Freshwater Sole
Brackish Tolerant
Flow Preference
✓ Compatible
Florida Flagfish
Low
Freshwater Sole
Low
Min Tank Volume
Combined: 110 L
Florida Flagfish
75 L
Freshwater Sole
110 L
Swimming Level
Shared: 1 zone
Florida Flagfish
MiddleBottom
Freshwater Sole
Bottom
🏷️Behavior Tags
Florida Flagfish
Fin NipperAggressive to same species/look-alikesHyperactive / Fast SwimmerTerritorial (Defends specific area)
Freshwater Sole
Piscivore (Eats small/nano fish)Shrimp EaterFry PredatorDigger (Disturbs Substrate)Shy / Slow Moving (Easily Stressed)Nocturnal
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Can your tank handle Florida Flagfish 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.

Florida Flagfish
Freshwater Sole
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Behaviour & Temperament

Florida Flagfish is a moderately assertive species (5/10), while Freshwater Sole is generally mild-mannered (4/10). This modest difference means Florida Flagfish may occasionally assert dominance over Freshwater Sole.

Florida Flagfish and Freshwater Sole both frequent the 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.

Additional behavioural considerations to keep in mind: Hyperactive swimmers can stress shy, slow-moving species through constant motion.

Worth noting: Freshwater Sole is nocturnal and will be most active after lights-out, naturally reducing daytime encounters.

To improve the chances of a peaceful coexistence in this community tank: Provide a significantly larger tank (at least 50% more volume than the minimum) to allow both Florida Flagfish and Freshwater Sole to establish separate territories. Add plenty of line-of-sight breaks using driftwood, rocks, and dense planting to reduce territorial confrontations. A larger aquarium with ample hiding spots can help diffuse aggression and give the less dominant fish space to retreat. Keep fin nippers in larger groups to distribute nipping behaviour among conspecifics rather than tank mates.

Water Parameters

The safe temperature window for both species falls between 22°C and 26°C. Aim for the midpoint of this range (around 24.0°C) for optimal comfort.

Both fish can tolerate a pH between 6.5 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 10–15 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Florida Flagfish 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.

Because this pairing requires extra vigilance, include plenty of hiding spots — caves, driftwood, and dense plant clusters — so the less dominant fish can retreat when needed.

Specific environmental needs for this combination include: Established Algae (Otocinclus), 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.

Why This Pairing Needs Extra Planning in Practice

This pairing usually fails when the tank is treated like a standard mixed community and the caution flags are ignored. Florida Flagfish and Freshwater Sole need extra room, more cover, and closer observation during the first few weeks so small aggression, feeding, or territory issues do not snowball into a long-term problem.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Florida Flagfish and Freshwater Sole.

Show 10 more tank sizes

Frequently Asked Questions

Can Florida Flagfish and Freshwater Sole live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 110 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Florida Flagfish 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 Florida Flagfish and Freshwater Sole together?

Keep the aquarium between 22°C and 26°C. A target of around 24.0°C sits comfortably within both species' preferred ranges.

Are Florida Flagfish or Freshwater Sole aggressive?

Florida Flagfish is moderately assertive (5/10) and Freshwater Sole is generally mild-mannered (4/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Florida Flagfish and Freshwater Sole need?

Both species overlap in the 6.5–7.8 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Will Florida Flagfish nip Freshwater Sole's fins?

Florida Flagfish is a known fin nipper. If Freshwater Sole has long or flowing fins, there is a real risk of fin damage. Keeping Florida Flagfish in a larger group can help redirect nipping behaviour toward conspecifics.

How do I manage Florida Flagfish's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Florida Flagfish 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.

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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