🐠 Fish Compatibility Guide

Can Giant Danio Live With Molly?

⚠️ Use Caution — Compatibility Score: 70/100
70/100 — Use Caution

Compatibility Overview

Giant Danio and Molly 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 55 gallons), dense planting, and close monitoring are essential.

FactorGiant DanioMollyVerdict
Temperature72–82°F72–82°F✅ 72–82°F
pH Range6.5–7.57.5–8.5⚠️ 7.5–7.5 (narrow)
Temperamentsemipeaceful⚠️ Monitor
Adult Size2.0 in4 in⚠️ 2.0× difference
Min. Group1+3+See below
Min. Tank Size55 gallons (for both species)

✅ Compatibility Positives

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

⚠️ Caution Points

⚠️Their preferred pH ranges are difficult to reconcile.

Species Profiles

Giant Danio — Aquarium species

The Giant Danio is a vibrant and peaceful addition to the freshwater aquarium. Known for its striking red and blue colors, it is a popular choice for beginners and experienced aquarists alike. These fish are relatively easy to care for and can thrive in a well-maintained tank. They are best kept in groups of at least six to ensure their well-being and displa

→ Full Giant Danio care guide

Molly — Poecilia sphenops

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

→ Full Molly care guide

Frequently Asked Questions

Can Giant Danio live with Molly?

With significant caution and a larger tank. Giant Danio and Molly 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 55 gallons), dense planting, and close monitoring are essential.

What tank size do I need for Giant Danio and Molly together?

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

What temperature suits both Giant Danio and Molly?

72–82°F

Is a Giant Danio aggressive toward a Molly?

Giant Danio is semi and Molly 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.

FactorScore
Temperature100/100
Ph0/100
Temperament75/100
Adult Size72/100
Swim Zone68/100
Social Needs92/100

Tank size scenarios

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.