Can Beckford's Pencilfish and Maison Reef Peacock Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 6, 2026
Not Recommended

Beckford's Pencilfish and Maison Reef Peacock are not recommended as tank mates due to conflicting pH requirements. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

Beckford's Pencilfish

Nannostomus beckfordi

Maison Reef Peacock

Aulonocara stuartgranti "Maison Reef"

🐠Family Group
Beckford's Pencilfish
Characins
Maison Reef Peacock
Cichlids - African
Temperament
Beckford's Pencilfish
Peaceful (2/10)
Maison Reef Peacock
Semi-Aggressive (6/10)
Temperature
✓ Compatible
Beckford's Pencilfish
22–28°C
Maison Reef Peacock
24–28°C
pH Range
✗ No overlap
Beckford's Pencilfish
5–7.5
Maison Reef Peacock
7.8–8.6
Hardness (dGH)
✓ Compatible
Beckford's Pencilfish
1–15
Maison Reef Peacock
10–25
Water Type
✓ Compatible
Beckford's Pencilfish
Freshwater Only
Maison Reef Peacock
Freshwater Only
Flow Preference
✓ Compatible
Beckford's Pencilfish
Low
Maison Reef Peacock
Moderate
Min Tank Volume
Combined: 208 L
Beckford's Pencilfish
60 L
Maison Reef Peacock
208 L
Swimming Level
Shared: 1 zone
Beckford's Pencilfish
TopMiddle
Maison Reef Peacock
MiddleBottom
🏷️Behavior Tags
Beckford's Pencilfish
Nano / Bite-sized (Predation Risk)Hyperactive / Fast SwimmerJumper (Lid Required)Shy / Slow Moving (Easily Stressed)
Maison Reef Peacock
Territorial (Defends specific area)Aggressive to same species/look-alikesDigger (Disturbs Substrate)Hyperactive / Fast Swimmer
Stocking calculator

Can your tank handle Beckford's Pencilfish and Maison Reef Peacock?

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.

Beckford's Pencilfish
Maison Reef Peacock
Test both in my tank

Behaviour & Temperament

Beckford's Pencilfish is a peaceful species (2/10), while Maison Reef Peacock is moderately assertive (6/10). This notable difference means Maison Reef Peacock may occasionally assert dominance over Beckford's Pencilfish.

Beckford's Pencilfish and Maison Reef Peacock 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.

Worth noting: Beckford's Pencilfish is a known jumper, so a tight-fitting lid is essential.

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 Beckford's Pencilfish (5–7.5) and Maison Reef Peacock (7.8–8.6) do not overlap, making it impossible to satisfy both species simultaneously.

For general hardness, the shared comfort zone is 10–15 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Beckford's Pencilfish and Maison Reef Peacock together, plan for an aquarium of at least 208 litres with a minimum length of 120 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, Leaf Litter/Blackwater, Sand (Sifters), Smooth Gravel (Sensitive Barbels). 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

Beckford's Pencilfish and Maison Reef Peacock 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 Beckford's Pencilfish and Maison Reef Peacock.

Show 5 more tank sizes

Frequently Asked Questions

Can Beckford's Pencilfish and Maison Reef Peacock live together?

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

What size tank do Beckford's Pencilfish and Maison Reef Peacock need?

A minimum of 208 litres (tank length at least 120 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 Beckford's Pencilfish and Maison Reef Peacock 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 Beckford's Pencilfish or Maison Reef Peacock aggressive?

Beckford's Pencilfish is peaceful (2/10) and Maison Reef Peacock is moderately assertive (6/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.

What pH do Beckford's Pencilfish and Maison Reef Peacock need?

Their pH requirements do not overlap. Beckford's Pencilfish prefers 5–7.5, while Maison Reef Peacock needs 7.8–8.6. This makes them incompatible in the same water chemistry.

How do I manage Maison Reef Peacock's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Maison Reef Peacock space to claim a territory without encroaching on the other fish's area. Adding décor that divides the tank into distinct zones works especially well.

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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