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Compatibility

Compatibility brief

Can Celebes Rainbowfish live with Harlequin Rasbora?

Celebes Rainbowfish

Celebes Rainbowfish

Marosatherina ladigesi

peaceful~7cm
Harlequin Rasbora

Harlequin Rasbora

Trigonostigma heteromorpha

peaceful~5cm
VerdictCAUTION

Caution. Check the issues below before buying.

Celebes Rainbowfish + Harlequin Rasbora: Hardness preference mismatch. Celebes Rainbowfish prefers hard water and Harlequin Rasbora prefers soft water. One of them lives outside its comfort band long-term — pick the tank's water for the more sensitive species. Outcomes still depend on your tank shape, maintenance routine, and individual fish.

Compatibility score

72/100

Profile confidence: low

Order of checkstank volume vs adults → predation mouth gap → temperament / fin nipping → shared water windows.

Min tank

80L

Combined minimum footprint reference for these two species: about 80L (larger active fish often want more length).

Temperature
Range in °C22–27°C shared
Celebes RainbowfishHarlequin RasboraShared window
pH
Range7–7.5 shared
Celebes RainbowfishHarlequin RasboraShared window

Assessment details

  1. Compatible temperaments

    Both Celebes Rainbowfish and Harlequin Rasbora share a peaceful temperament.

  2. Compatible temperature range

    Both fish can comfortably share similar water temperatures.

  3. Hardness preference mismatch

    Top issue

    Celebes Rainbowfish prefers hard water and Harlequin Rasbora prefers soft water. One of them lives outside its comfort band long-term — pick the tank's water for the more sensitive species.

“Celebes Rainbowfish prefers hard water and Harlequin Rasbora…”

Hardness preference mismatch

Next steps

Concrete changes, not "research more" filler.

  • •Celebes Rainbowfish should be kept in a group of at least 6 for best health and behaviour.
  • •Harlequin Rasbora should be kept in a group of at least 6 for best health and behaviour.
Sources from both profiles
Only URLs that exist on the species records are shown. We do not fabricate citations.

Try this next

Build the full stocking list with Celebes Rainbowfish + Harlequin Rasbora

Compare another pairOpen tank builder

Plan further

Check each species’ mates list, size the glass, then verify the full stock in the builder. Methodology explains how verdicts are produced.

Individual fish vary in personality. Fishori uses conservative hobby rules. Observe any new introduction closely, feed thoughtfully, and keep a quarantine or backup plan. This is not veterinary advice.

Profile data confidence: medium. Driven by the lower-confidence profile (Celebes Rainbowfish): Typical care sources — real tanks still vary.

Full tank-mate guides

Related pair checks

Celebes Rainbowfish + Harlequin Rasbora — common questions

Can Celebes Rainbowfish live with Harlequin Rasbora?
Yes, if you plan for it. The verdict is CAUTION, which means the pairing works when specific conditions are met, not by default. The first condition: Celebes Rainbowfish should be kept in a group of at least 6 for best health and behaviour.
What tank size do you need for Celebes Rainbowfish and Harlequin Rasbora together?
Plan around 80 litres as the working minimum. That figure comes from each species' published minimum and their group needs, and it assumes adult sizes, not shop sizes.
What's the main risk?
Hardness preference mismatch. That is the first thing to plan around. The matching entry under assessment details on this page explains the reasoning and the numbers behind it.
What should you check before buying?
Harlequin Rasbora should be kept in a group of at least 6 for best health and behaviour.