๐Ÿ  Fish Compatibility Guide

Can Congo Tetra and Molly Live Together?

Updated September 23, 2026 ยท FishCare AI Editorial Team

โš ๏ธ Use Caution โ€” Compatibility Score: 65/100
65/100 โ€” Use Caution

Congo Tetra and Molly Compatibility Overview

Congo Tetra and Molly can potentially coexist, but the combination requires careful attention. Their usable pH overlap is narrow and requires stable, tested water. A larger tank (minimum 55 gallons), dense planting, and close monitoring are essential.

Compatibility factors for Congo Tetra and Molly
FactorCongo TetraMollyVerdict
Temperature73โ€“82ยฐF72โ€“82ยฐFโœ… 73โ€“82ยฐF
pH Range6.0โ€“7.57.5โ€“8.5โš ๏ธ 7.5โ€“7.5 (narrow)
Temperamentpeacefulpeacefulโœ… Compatible
Adult Size3.1 in4 inโœ… Similar
Min. Group6+3+See below
Min. Tank Size55 gallons (for both species)โ€”

Compatibility Positives

A stable shared temperature range is available.
Temperament risk is relatively low when normal group sizes are maintained.

Caution Points

Their usable pH overlap is narrow and requires stable, tested water.

Species Profiles

Congo Tetra โ€” Phenacogrammus interruptus

Congo Tetra and Molly compatibility โ€” Congo Tetra

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.

โ†’ Full Congo Tetra care guide

Molly โ€” Poecilia sphenops

Congo Tetra and Molly compatibility โ€” Molly

Hardy livebearers that prefer alkaline, hard water โ€” sometimes slightly brackish. Prolific breeders; peaceful community fish.

โ†’ Full Molly care guide

Frequently Asked Questions

Can Congo Tetra live with Molly?

With significant caution and a larger tank. Congo Tetra and Molly can potentially coexist, but the combination requires careful attention. Their usable pH overlap is narrow and requires stable, tested water. A larger tank (minimum 55 gallons), dense planting, and close monitoring are essential.

What tank size do I need for Congo Tetra and Molly together?

A minimum of 55 gallons is recommended for keeping Congo Tetra and Molly together. A larger tank improves water stability and reduces territorial conflict.

What temperature suits both Congo Tetra and Molly?

73โ€“82ยฐF โ€” inside Congo Tetra's 73โ€“82ยฐF and Molly's 72โ€“82ยฐF.

Is a Congo Tetra aggressive toward a Molly?

Congo Tetra is peaceful and Molly is peaceful. No major aggression issues are expected between these species.

Related Compatibility Guides

Tank Size for Congo Tetra and Molly

Use the scenario that matches the actual group sizes and temperament you plan to keep.

ScenarioTankWhen it applies
Minimum viable55 galOnly for the recommended minimum groups, mature filtration, and close monitoring.
Recommended community75 galAdds territory, swimming room, and a safer buffer for behavior.
Low-conflict setup125 galBest when keeping larger schools or reducing territorial pressure.