Can Leopoldi Stingray (Black Diamond) and Molly (Sailfin/Black/Dalmatian) Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 6, 2026
Not Recommended

Leopoldi Stingray (Black Diamond) and Molly (Sailfin/Black/Dalmatian) are not recommended as tank mates due to 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

Leopoldi Stingray (Black Diamond)

Potamotrygon leopoldi

Molly (Sailfin/Black/Dalmatian)

Poecilia sphenops

🐠Family Group
Leopoldi Stingray (Black Diamond)
Oddballs
Molly (Sailfin/Black/Dalmatian)
Livebearers
Temperament
Leopoldi Stingray (Black Diamond)
Semi-Aggressive (5/10)
Molly (Sailfin/Black/Dalmatian)
Mostly Peaceful (3/10)
Temperature
✓ Compatible
Leopoldi Stingray (Black Diamond)
26–30°C
Molly (Sailfin/Black/Dalmatian)
24–28°C
pH Range
✓ Compatible
Leopoldi Stingray (Black Diamond)
6–7.5
Molly (Sailfin/Black/Dalmatian)
7.5–8.5
Hardness (dGH)
✗ No overlap
Leopoldi Stingray (Black Diamond)
3–10
Molly (Sailfin/Black/Dalmatian)
12–30
Water Type
✓ Compatible
Leopoldi Stingray (Black Diamond)
Freshwater Only
Molly (Sailfin/Black/Dalmatian)
Brackish Tolerant
Flow Preference
✓ Compatible
Leopoldi Stingray (Black Diamond)
Moderate
Molly (Sailfin/Black/Dalmatian)
Moderate
Min Tank Volume
Combined: 1135 L
Leopoldi Stingray (Black Diamond)
1135 L
Molly (Sailfin/Black/Dalmatian)
75 L
Swimming Level
✓ Different zones
Leopoldi Stingray (Black Diamond)
Bottom
Molly (Sailfin/Black/Dalmatian)
TopMiddle
🏷️Behavior Tags
Leopoldi Stingray (Black Diamond)
Piscivore (Eats small/nano fish)Shrimp EaterFry PredatorDigger (Disturbs Substrate)Hyperactive / Fast Swimmer
Molly (Sailfin/Black/Dalmatian)
Hyperactive / Fast SwimmerFry PredatorAggressive Eater (Starves shy fish)
Stocking calculator

Can your tank handle Leopoldi Stingray (Black Diamond) and Molly (Sailfin/Black/Dalmatian)?

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.

Leopoldi Stingray (Black Diamond)
Molly (Sailfin/Black/Dalmatian)
Test both in my tank

Behaviour & Temperament

Leopoldi Stingray (Black Diamond) is a moderately assertive species (5/10), while Molly (Sailfin/Black/Dalmatian) is generally mild-mannered (3/10). This modest difference means Leopoldi Stingray (Black Diamond) may occasionally assert dominance over Molly (Sailfin/Black/Dalmatian).

In terms of spatial distribution, Leopoldi Stingray (Black Diamond) prefers the Bottom (Substrate) zone, whereas Molly (Sailfin/Black/Dalmatian) occupies the Top (Surface) and Middle (Open Water) zones. Because they use different levels of the water column, territorial disputes are less likely and the tank will appear more balanced.

Water Parameters

The safe temperature window for both species falls between 26°C and 28°C. Aim for the midpoint of this range (around 27.0°C) for optimal comfort.

Both fish can tolerate a pH between 7.5 and 7.5. Maintaining a stable value within this band is more important than hitting an exact number.

Hardness requirements are incompatible: Leopoldi Stingray (Black Diamond) needs 3–10 dGH while Molly (Sailfin/Black/Dalmatian) requires 12–30 dGH.

Tank Setup

To house Leopoldi Stingray (Black Diamond) and Molly (Sailfin/Black/Dalmatian) together, plan for an aquarium of at least 1135 litres with a minimum length of 240 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: Sand (Sifters), Smooth Gravel (Sensitive Barbels), Plants - Densely covered, Established Algae (Otocinclus). Meeting these requirements will help both species thrive.

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

Why This Pairing Usually Fails in Practice

Leopoldi Stingray (Black Diamond) and Molly (Sailfin/Black/Dalmatian) 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.

Frequently Asked Questions

Can Leopoldi Stingray (Black Diamond) and Molly (Sailfin/Black/Dalmatian) live together?

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

What size tank do Leopoldi Stingray (Black Diamond) and Molly (Sailfin/Black/Dalmatian) need?

A minimum of 1135 litres (tank length at least 240 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 Leopoldi Stingray (Black Diamond) and Molly (Sailfin/Black/Dalmatian) together?

Keep the aquarium between 26°C and 28°C. A target of around 27.0°C sits comfortably within both species' preferred ranges.

Are Leopoldi Stingray (Black Diamond) or Molly (Sailfin/Black/Dalmatian) aggressive?

Leopoldi Stingray (Black Diamond) is moderately assertive (5/10) and Molly (Sailfin/Black/Dalmatian) is generally mild-mannered (3/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Leopoldi Stingray (Black Diamond) and Molly (Sailfin/Black/Dalmatian) need?

Both species overlap in the 7.5–7.5 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Editorial Review

Guidarium Editorial Desk

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

Last reviewed
May 6, 2026
Last updated
May 6, 2026
Issues or corrections?
Contact the editorial team

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