Can Dusky Millions Fish and Schwartz's Cory Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 6, 2026
Ideal Tank Mates

Yes, Dusky Millions Fish and Schwartz's Cory are ideal tank mates. Both species share compatible water parameters and peaceful temperaments, making them well-suited for a community aquarium. They occupy different areas of the water column, which reduces competition for space. A minimum tank size of 60 litres is recommended.


At a Glance

Dusky Millions Fish

Phalloceros caudimaculatus

Schwartz's Cory

Corydoras schwartzi

🐠Family Group
Dusky Millions Fish
Livebearers
Schwartz's Cory
Catfish
Temperament
Dusky Millions Fish
Peaceful (2/10)
Schwartz's Cory
Peaceful (1/10)
Temperature
✓ Compatible
Dusky Millions Fish
16–24°C
Schwartz's Cory
22–26°C
pH Range
✓ Compatible
Dusky Millions Fish
7–8
Schwartz's Cory
6–7.5
Hardness (dGH)
✓ Compatible
Dusky Millions Fish
8–20
Schwartz's Cory
2–15
Water Type
✓ Compatible
Dusky Millions Fish
Brackish Tolerant
Schwartz's Cory
Freshwater Only
Flow Preference
✓ Compatible
Dusky Millions Fish
Low
Schwartz's Cory
Moderate
Min Tank Volume
Combined: 60 L
Dusky Millions Fish
40 L
Schwartz's Cory
60 L
Swimming Level
✓ Different zones
Dusky Millions Fish
TopMiddle
Schwartz's Cory
Bottom
🏷️Behavior Tags
Dusky Millions Fish
Hyperactive / Fast SwimmerPlant DestroyerFin Nipper
Schwartz's Cory
Hyperactive / Fast Swimmer
Stocking calculator

Can your tank handle Dusky Millions Fish and Schwartz's Cory?

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.

Dusky Millions Fish
Schwartz's Cory
Test both in my tank

Behaviour & Temperament

Dusky Millions Fish is a peaceful species (2/10), while Schwartz's Cory is peaceful (1/10). This modest difference means Dusky Millions Fish may occasionally assert dominance over Schwartz's Cory.

In terms of spatial distribution, Dusky Millions Fish prefers the Top (Surface) and Middle (Open Water) zones, whereas Schwartz's Cory occupies the Bottom (Substrate) zone. 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 22°C and 24°C. Aim for the midpoint of this range (around 23.0°C) for optimal comfort.

Both fish can tolerate a pH between 7 and 7.5. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 8–15 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Dusky Millions Fish and Schwartz's Cory together, plan for an aquarium of at least 60 litres with a minimum length of 60 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: Plants - Densely covered, Plants - Floating, Established Algae (Otocinclus), Sand (Sifters). 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 Works in Practice

Dusky Millions Fish and Schwartz's Cory work best when the tank gives each fish enough room to use its preferred level of the aquarium and enough cover to avoid constant visual contact. The score matters, but the real-world success usually comes from matching their pace, keeping water stable, and resisting the urge to crowd the tank just because the pair looks safe on paper.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Dusky Millions Fish and Schwartz's Cory.

Show 19 more tank sizes

Frequently Asked Questions

Can Dusky Millions Fish and Schwartz's Cory live together?

Yes. Dusky Millions Fish and Schwartz's Cory are considered ideal tank mates. Their water parameters, temperaments, and behaviour profiles are well matched for a community aquarium.

What size tank do Dusky Millions Fish and Schwartz's Cory need?

A minimum of 60 litres (tank length at least 60 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 Dusky Millions Fish and Schwartz's Cory together?

Keep the aquarium between 22°C and 24°C. A target of around 23.0°C sits comfortably within both species' preferred ranges.

Are Dusky Millions Fish or Schwartz's Cory aggressive?

Dusky Millions Fish is peaceful (2/10) and Schwartz's Cory is peaceful (1/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Dusky Millions Fish and Schwartz's Cory need?

Both species overlap in the 7–7.5 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Will Dusky Millions Fish nip Schwartz's Cory's fins?

Dusky Millions Fish is a known fin nipper. If Schwartz's Cory has long or flowing fins, there is a real risk of fin damage. Keeping Dusky Millions Fish in a larger group can help redirect nipping behaviour toward conspecifics.

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

Related Comparisons