Compatibility Overview
Harlequin Rasbora and Pea Puffer can generally share an aquarium with appropriate planning. Both species prefer overlapping temperature and pH ranges, and neither poses a major aggression risk to the other. A minimum 40-gallon tank is recommended to provide adequate territory and water volume for both species.
| Factor | Harlequin Rasbora | Pea Puffer | Verdict |
|---|---|---|---|
| Temperature | 72–81°F | 74–82°F | ✅ 74–81°F |
| pH Range | 5.5–7.5 | 7.0–8.0 | ⚠️ 7.0–7.5 (narrow) |
| Temperament | peaceful | semi | ⚠️ Monitor |
| Adult Size | 1.75 in | 1 in | ✅ Similar |
| Min. Group | 8+ | 1+ | See below |
| Min. Tank Size | 40 gallons (for both species) | — | |
✅ Compatibility Positives
⚠️ Caution Points
Species Profiles
Harlequin Rasbora — Trigonostigma heteromorpha
Active mid-level schooling fish with a distinctive black triangular patch. One of the best all-around community tank fish.
→ Full Harlequin Rasbora care guide
Pea Puffer — Carinotetraodon travancoricus
World's smallest pufferfish — intensely territorial and nippy despite tiny size. Will attack fins and eat shrimp and snails.
Frequently Asked Questions
Can Harlequin Rasbora live with Pea Puffer?
Yes, in a well-planned setup. Harlequin Rasbora and Pea Puffer can generally share an aquarium with appropriate planning. Both species prefer overlapping temperature and pH ranges, and neither poses a major aggression risk to the other. A minimum 40-gallon tank is recommended to provide adequate territory and water volume for both species.
What tank size do I need for Harlequin Rasbora and Pea Puffer together?
A minimum of 40 gallons is recommended for keeping Harlequin Rasbora and Pea Puffer together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Harlequin Rasbora and Pea Puffer?
74–81°F
Is a Harlequin Rasbora aggressive toward a Pea Puffer?
Harlequin Rasbora is peaceful and Pea Puffer is semi. Limited pH overlap (7.0–7.5) — maintain pH carefully within this narrow window.