Can Green Neon Tetra and Sailfin Molly Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 11, 2026
Not Recommended

Green Neon Tetra and Sailfin Molly are not recommended as tank mates due to conflicting pH requirements and incompatible hardness ranges. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

Green Neon Tetra

Paracheirodon simulans

Sailfin Molly

Poecilia latipinna

🐠Family Group
Green Neon Tetra
Characins
Sailfin Molly
Livebearers
Temperament
Green Neon Tetra
Peaceful (0/10)
Sailfin Molly
Mostly Peaceful (3/10)
Temperature
✓ Compatible
Green Neon Tetra
24–29°C
Sailfin Molly
22–28°C
pH Range
✗ No overlap
Green Neon Tetra
4.5–6.5
Sailfin Molly
7.5–8.5
Hardness (dGH)
✗ No overlap
Green Neon Tetra
1–8
Sailfin Molly
15–30
Water Type
✓ Compatible
Green Neon Tetra
Freshwater Only
Sailfin Molly
Brackish Tolerant
Flow Preference
✓ Compatible
Green Neon Tetra
Low
Sailfin Molly
Moderate
Min Tank Volume
Combined: 110 L
Green Neon Tetra
38 L
Sailfin Molly
110 L
Swimming Level
Shared: 1 zone
Green Neon Tetra
Middle
Sailfin Molly
TopMiddleBottom
🏷️Behavior Tags
Green Neon Tetra
Nano / Bite-sized (Predation Risk)Shy / Slow Moving (Easily Stressed)
Sailfin Molly
Hyperactive / Fast SwimmerFry PredatorAggressive Eater (Starves shy fish)
Stocking calculator

Can your tank handle Green Neon Tetra and Sailfin Molly?

Compatibility is only part of the answer. Test both fish with your real tank size, current stock, and maintenance needs to see if you have enough space and a safe stocking level before you add them.

Green Neon Tetra
Sailfin Molly
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Behaviour & Temperament

Green Neon Tetra is a peaceful species (0/10), while Sailfin Molly is generally mild-mannered (3/10). This modest difference means Sailfin Molly may occasionally assert dominance over Green Neon Tetra.

Green Neon Tetra and Sailfin Molly both frequent the Middle (Open Water) region of the setup. This overlap can increase competition for space, so providing ample room and cover is important to keep both species comfortable.

Additional behavioural considerations to keep in mind: Hyperactive swimmers can stress shy, slow-moving species through constant motion. Aggressive eaters may outcompete shy fish for food, leading to malnutrition.

Water Parameters

The safe temperature window for both species falls between 24°C and 28°C. Aim for the midpoint of this range (around 26.0°C) for optimal comfort.

The pH requirements of Green Neon Tetra (4.5–6.5) and Sailfin Molly (7.5–8.5) do not overlap, making it impossible to satisfy both species simultaneously.

Hardness requirements are incompatible: Green Neon Tetra needs 1–8 dGH while Sailfin Molly requires 15–30 dGH.

Tank Setup

To house Green Neon Tetra and Sailfin Molly together, plan for an aquarium of at least 110 litres with a minimum length of 80 cm. This recommendation combines the stricter species minimums with a community-load allowance so the pairing has realistic long-term space and filtration headroom.

Providing a mix of open swimming space and sheltered areas with rocks, driftwood, or plants will keep both species comfortable and allow natural behaviour.

Specific environmental needs for this combination include: Leaf Litter/Blackwater, Plants - Densely covered, Plants - Floating, Established Algae (Otocinclus). Meeting these requirements will help both species thrive.

Both species do well with low (still water) water movement, so a standard filtration setup rated for the tank volume should suffice.

Why This Pairing Usually Fails in Practice

Green Neon Tetra and Sailfin Molly are the kind of pair that can look acceptable in a shop but become a maintenance problem at home. The main risk is not a single number in the chart; it is the way incompatible behavior, water needs, or pressure on space compounds over time once both fish are established in the same tank.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Green Neon Tetra and Sailfin Molly.

Show 12 more tank sizes

Diet & Feeding

Feeding time deserves special attention with this pairing. Sailfin Molly is an aggressive eater that may prevent Green Neon Tetra from getting enough food.

Because Sailfin Molly is a fast, competitive feeder, consider using sinking pellets or feeding at opposite ends of the setup to ensure Green Neon Tetra receives an adequate share.

Frequently Asked Questions

Can Green Neon Tetra and Sailfin Molly live together?

No. This combination is not recommended. Key incompatibilities — such as critical behavioural conflicts — make cohabitation unsafe.

What size tank do Green Neon Tetra and Sailfin Molly need?

A minimum of 110 litres (tank length at least 80 cm) is recommended. This provides enough space for both species to establish their own areas and reduces the likelihood of territorial disputes.

What water temperature is best for Green Neon Tetra and Sailfin Molly together?

Keep the aquarium between 24°C and 28°C. A target of around 26.0°C sits comfortably within both species' preferred ranges.

Are Green Neon Tetra or Sailfin Molly aggressive?

Green Neon Tetra is peaceful (0/10) and Sailfin Molly is generally mild-mannered (3/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Green Neon Tetra and Sailfin Molly need?

Their pH requirements do not overlap. Green Neon Tetra prefers 4.5–6.5, while Sailfin Molly needs 7.5–8.5. This makes them incompatible in the same water chemistry.

Editorial Review

Guidarium Editorial Desk

Reviewed against Guidarium care, stocking, and compatibility standards. Read the editorial policy.

Last reviewed
May 11, 2026
Last updated
May 11, 2026
Issues or corrections?
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