Can Florida Flagfish and Redline Rasbora Live Together?
Florida Flagfish and Redline Rasbora are not recommended as tank mates due to incompatible hardness ranges. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.
At a Glance
Can your tank handle Florida Flagfish and Redline Rasbora?
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.
Behaviour & Temperament
Florida Flagfish is a moderately assertive species (5/10), while Redline Rasbora is peaceful (1/10). This notable difference means Florida Flagfish may occasionally assert dominance over Redline Rasbora.
Florida Flagfish and Redline Rasbora 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.
Additional behavioural considerations to keep in mind: Hyperactive swimmers can stress shy, slow-moving species through constant motion.
Worth noting: Redline Rasbora is a known jumper, so a tight-fitting lid is essential.
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 6.8. Maintaining a stable value within this band is more important than hitting an exact number.
Hardness requirements are incompatible: Florida Flagfish needs 10–25 dGH while Redline Rasbora requires 1–8 dGH.
Tank Setup
To house Florida Flagfish and Redline Rasbora together, plan for an aquarium of at least 80 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: Established Algae (Otocinclus), Plants - Densely covered, Leaf Litter/Blackwater, Driftwood (Digestion/Hiding), Plants - Floating. 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 Usually Fails in Practice
Florida Flagfish and Redline Rasbora 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 Florida Flagfish and Redline Rasbora.
30 Gallon Breeder
40 Gallon Breeder
55 Gallon Standard
60 Gallon Breeder
75 Gallon Standard
90 Gallon Standard
Show 12 more tank sizes
Frequently Asked Questions
Can Florida Flagfish and Redline Rasbora live together?
No. This combination is not recommended. Key incompatibilities — such as critical behavioural conflicts — make cohabitation unsafe.
What size tank do Florida Flagfish and Redline Rasbora need?
A minimum of 80 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 Florida Flagfish and Redline Rasbora 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 Redline Rasbora aggressive?
Florida Flagfish is moderately assertive (5/10) and Redline Rasbora is peaceful (1/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.
What pH do Florida Flagfish and Redline Rasbora need?
Both species overlap in the 6.5–6.8 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.
Will Florida Flagfish nip Redline Rasbora's fins?
Florida Flagfish is a known fin nipper. If Redline Rasbora 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.
Shared setup supplies
We may earn from qualifying purchases
Guidarium Editorial Desk
Reviewed against Guidarium care, stocking, and compatibility standards. Read the editorial policy.
- Last reviewed
- May 11, 2026
- Last updated
- May 11, 2026
- Issues or corrections?
- Contact the editorial team
Related Comparisons
Florida Flagfish & Rachov's Killifish (Annual)
·
Florida Flagfish & Gardner's Killifish
·
Florida Flagfish & Golden Wonder Killifish
·
Florida Flagfish & Lyretail Killifish
·
Florida Flagfish & Gangetic Leaf Fish
·
Florida Flagfish & Orange Chromide
·
Redline Rasbora & Brilliant Rasbora
·
Redline Rasbora & Cherry Spot Rasbora
·
Redline Rasbora & Chili Rasbora
·
Redline Rasbora & Emerald Eye Rasbora
·
Redline Rasbora & Espei Rasbora (Lambchop Rasbora)
·
Redline Rasbora & Nana Rasbora
·