Compatibility Overview
Discus and Otocinclus 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 | Discus | Otocinclus | Verdict |
|---|---|---|---|
| Temperature | 82–88°F | 72–82°F | ⚠️ 82–82°F (narrow) |
| pH Range | 5.0–7.0 | 6.0–7.5 | ✅ 6.0–7.0 |
| Temperament | semi | peaceful | ⚠️ Monitor |
| Adult Size | 8 in | 1.5 in | ❌ 5× difference |
| Min. Group | 5+ | 4+ | See below |
| Min. Tank Size | 100 gallons (for both species) | — | |
✅ Compatibility Positives
❌ Incompatibility Reasons
Species Profiles
Discus — Symphysodon spp.
The 'king of the aquarium' — beautiful but demanding. Requires very warm, soft, acidic water that excludes most community fish.
Otocinclus — Otocinclus spp.
Tiny algae-eating catfish that are peaceful with all species. Need established algae growth and biofilm; sensitive to ammonia.
Frequently Asked Questions
Can Discus live with Otocinclus?
Generally not recommended. Discus and Otocinclus 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 Discus and Otocinclus together?
A minimum of 100 gallons is recommended for keeping Discus and Otocinclus together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Discus and Otocinclus?
82–82°F (narrow)
Is a Discus aggressive toward a Otocinclus?
Discus is semi and Otocinclus is peaceful. Minimal temperature overlap (82–82°F) — difficult to satisfy both species simultaneously.