Compatibility Overview
Chili Rasbora and Oscar are generally not recommended to be housed together. The issues listed above — whether water parameter incompatibility, predation risk, or aggression — create conditions where one or both fish are likely to suffer harm or chronic stress.
| Factor | Chili Rasbora | Oscar | Verdict |
|---|---|---|---|
| Temperature | 68–82°F | 74–81°F | ✅ 74–81°F |
| pH Range | 4.0–7.0 | 6.0–8.0 | ✅ 6.0–7.0 |
| Temperament | peaceful | aggressive | ❌ Risk |
| Adult Size | 0.8 in | 14 in | ❌ 18× difference |
| Min. Group | 8+ | 1+ | See below |
| Min. Tank Size | 100 gallons (for both species) | — | |
✅ Compatibility Positives
❌ Incompatibility Reasons
Species Profiles
Chili Rasbora — Boraras brigittae
Vivid red nano fish from Borneo blackwater habitats. Extremely small — only safe with fish too small to swallow them.
→ Full Chili Rasbora care guide
Oscar — Astronotus ocellatus
Intelligent but aggressive cichlids that will eat any fish small enough to fit in their mouth. Require large tanks (75+ gallons) and robust tank mates.
Frequently Asked Questions
Can Chili Rasbora live with Oscar?
Generally not recommended. Chili Rasbora and Oscar are generally not recommended to be housed together. The issues listed above — whether water parameter incompatibility, predation risk, or aggression — create conditions where one or both fish are likely to suffer harm or chronic stress.
What tank size do I need for Chili Rasbora and Oscar together?
A minimum of 100 gallons is recommended for keeping Chili Rasbora and Oscar together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Chili Rasbora and Oscar?
74–81°F
Is a Chili Rasbora aggressive toward a Oscar?
Chili Rasbora is peaceful and Oscar is aggressive. Oscars will eat chili rasboras.