Compatibility Overview
Congo Tetra and Guppy can potentially coexist, but the combination requires careful attention. Some combination of water parameter differences, size mismatch, or temperament issues make this pair challenging. A larger tank (minimum 40 gallons), dense planting, and close monitoring are essential.
| Factor | Congo Tetra | Guppy | Verdict |
|---|---|---|---|
| Temperature | 72–79°F | 72–82°F | ✅ 72–79°F |
| pH Range | 6.0–7.0 | 6.8–8.5 | ⚠️ 6.8–7.0 (narrow) |
| Temperament | aggressive | peaceful | ❌ Risk |
| Adult Size | 1.6 in | 2.5 in | ✅ Similar |
| Min. Group | 6+ | 3+ | See below |
| Min. Tank Size | 40 gallons (for both species) | — | |
✅ Compatibility Positives
⚠️ Caution Points
Species Profiles
Congo Tetra — Aquarium species
The Congo Tetra is a vibrant and active fish that thrives in a well-maintained freshwater aquarium. With its striking coloration and peaceful nature, it's a great addition to any community tank. This species is best kept in groups and requires a spacious tank with plenty of swimming space. They are known for their playful nature and can be seen darting aroun
Guppy — Poecilia reticulata
Hardy and colourful livebearers. Males' long flowing tails make them targets for fin-nipping species. Very prolific breeders.
Frequently Asked Questions
Can Congo Tetra live with Guppy?
With significant caution and a larger tank. Congo Tetra and Guppy can potentially coexist, but the combination requires careful attention. Some combination of water parameter differences, size mismatch, or temperament issues make this pair challenging. A larger tank (minimum 40 gallons), dense planting, and close monitoring are essential.
What tank size do I need for Congo Tetra and Guppy together?
A minimum of 40 gallons is recommended for keeping Congo Tetra and Guppy together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Congo Tetra and Guppy?
72–79°F
Is a Congo Tetra aggressive toward a Guppy?
Congo Tetra is aggressive and Guppy is peaceful. Their preferred pH ranges are difficult to reconcile.
Related Compatibility Guides
Compatibility score breakdown
The overall score is weighted across water chemistry, behavior, adult size, swimming zone, and social needs. A score is a planning aid—not a guarantee for individual fish.
| Factor | Score |
|---|---|
| Temperature | 100/100 |
| Ph | 20/100 |
| Temperament | 30/100 |
| Adult Size | 100/100 |
| Swim Zone | 68/100 |
| Social Needs | 85/100 |
Tank size scenarios
Use the scenario that matches the actual group sizes and temperament you plan to keep.
| Scenario | Tank | When it applies |
|---|---|---|
| Minimum viable | 40 gal | Only for the recommended minimum groups, mature filtration, and close monitoring. |
| Recommended community | 55 gal | Adds territory, swimming room, and a safer buffer for behavior. |
| Low-conflict setup | 90 gal | Best when keeping larger schools or reducing territorial pressure. |