Can Bladder Snail (Pest Snail) and Dusky Millions Fish Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 4, 2026
Ideal Tank Mates

Yes, Bladder Snail (Pest Snail) and Dusky Millions Fish are ideal tank mates. Both species share compatible water parameters and peaceful temperaments, making them well-suited for a community aquarium. A minimum tank size of 40 litres is recommended.


At a Glance

Bladder Snail (Pest Snail)

Physella acuta

Dusky Millions Fish

Phalloceros caudimaculatus

🐠Family Group
Bladder Snail (Pest Snail)
Invertebrates
Dusky Millions Fish
Livebearers
Temperament
Bladder Snail (Pest Snail)
Peaceful (0/10)
Dusky Millions Fish
Peaceful (2/10)
Temperature
✓ Compatible
Bladder Snail (Pest Snail)
10–30°C
Dusky Millions Fish
16–24°C
pH Range
✓ Compatible
Bladder Snail (Pest Snail)
6–8.5
Dusky Millions Fish
7–8
Hardness (dGH)
✓ Compatible
Bladder Snail (Pest Snail)
4–20
Dusky Millions Fish
8–20
Water Type
✓ Compatible
Bladder Snail (Pest Snail)
Freshwater Only
Dusky Millions Fish
Brackish Tolerant
Flow Preference
✓ Compatible
Bladder Snail (Pest Snail)
Low
Dusky Millions Fish
Low
Min Tank Volume
Combined: 40 L
Bladder Snail (Pest Snail)
2 L
Dusky Millions Fish
40 L
Swimming Level
Shared: 2 zones
Bladder Snail (Pest Snail)
TopMiddleBottom
Dusky Millions Fish
TopMiddle
🏷️Behavior Tags
Bladder Snail (Pest Snail)
Nano / Bite-sized (Predation Risk)Hyperactive / Fast Swimmer
Dusky Millions Fish
Hyperactive / Fast SwimmerPlant DestroyerFin Nipper
Stocking calculator

Can your tank handle Bladder Snail (Pest Snail) and Dusky Millions Fish?

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.

Bladder Snail (Pest Snail)
Dusky Millions Fish
Test both in my tank

Behaviour & Temperament

Bladder Snail (Pest Snail) is a peaceful species (0/10), while Dusky Millions Fish is peaceful (2/10). This modest difference means Dusky Millions Fish may occasionally assert dominance over Bladder Snail (Pest Snail).

Bladder Snail (Pest Snail) and Dusky Millions Fish both frequent the Top (Surface) and 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.

Water Parameters

The safe temperature window for both species falls between 16°C and 24°C. Aim for the midpoint of this range (around 20.0°C) for optimal comfort.

Both fish can tolerate a pH between 7 and 8. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 8–20 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Bladder Snail (Pest Snail) and Dusky Millions Fish together, plan for an aquarium of at least 40 litres with a minimum length of 45 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: Established Algae (Otocinclus), Plants - Densely covered, Plants - Floating. 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

Bladder Snail (Pest Snail) and Dusky Millions Fish 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 Bladder Snail (Pest Snail) and Dusky Millions Fish.

Show 21 more tank sizes

Frequently Asked Questions

Can Bladder Snail (Pest Snail) and Dusky Millions Fish live together?

Yes. Bladder Snail (Pest Snail) and Dusky Millions Fish are considered ideal tank mates. Their water parameters, temperaments, and behaviour profiles are well matched for a community aquarium.

What size tank do Bladder Snail (Pest Snail) and Dusky Millions Fish need?

A minimum of 40 litres (tank length at least 45 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 Bladder Snail (Pest Snail) and Dusky Millions Fish together?

Keep the aquarium between 16°C and 24°C. A target of around 20.0°C sits comfortably within both species' preferred ranges.

Are Bladder Snail (Pest Snail) or Dusky Millions Fish aggressive?

Bladder Snail (Pest Snail) is peaceful (0/10) and Dusky Millions Fish is peaceful (2/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Bladder Snail (Pest Snail) and Dusky Millions Fish need?

Both species overlap in the 7–8 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Will Dusky Millions Fish nip Bladder Snail (Pest Snail)'s fins?

Dusky Millions Fish is a known fin nipper. If Bladder Snail (Pest Snail) 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 4, 2026
Last updated
May 4, 2026
Issues or corrections?
Contact the editorial team

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