Can Beckford's Pencilfish and Pearl Eartheater Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 11, 2026
Possible with Caution

Keeping Beckford's Pencilfish and Pearl Eartheater together is possible but requires caution due to differing aggression levels. Provide a spacious tank of at least 250 litres with plenty of hiding spots to reduce stress. Monitor behaviour closely, especially during the first few weeks.


At a Glance

Beckford's Pencilfish

Nannostomus beckfordi

Pearl Eartheater

Geophagus brasiliensis

🐠Family Group
Beckford's Pencilfish
Characins
Pearl Eartheater
Cichlids - South American
Temperament
Beckford's Pencilfish
Peaceful (2/10)
Pearl Eartheater
Semi-Aggressive (6/10)
Temperature
✓ Compatible
Beckford's Pencilfish
22–28°C
Pearl Eartheater
20–28°C
pH Range
✓ Compatible
Beckford's Pencilfish
5–7.5
Pearl Eartheater
6–8
Hardness (dGH)
✓ Compatible
Beckford's Pencilfish
1–15
Pearl Eartheater
5–20
Water Type
✓ Compatible
Beckford's Pencilfish
Freshwater Only
Pearl Eartheater
Brackish Tolerant
Flow Preference
✓ Compatible
Beckford's Pencilfish
Low
Pearl Eartheater
Moderate
Min Tank Volume
Combined: 250 L
Beckford's Pencilfish
60 L
Pearl Eartheater
250 L
Swimming Level
Shared: 1 zone
Beckford's Pencilfish
TopMiddle
Pearl Eartheater
BottomMiddle
🏷️Behavior Tags
Beckford's Pencilfish
Nano / Bite-sized (Predation Risk)Hyperactive / Fast SwimmerJumper (Lid Required)Shy / Slow Moving (Easily Stressed)
Pearl Eartheater
Digger (Disturbs Substrate)Plant DestroyerTerritorial (Defends specific area)Fry PredatorAggressive to same species/look-alikes
Stocking calculator

Can your tank handle Beckford's Pencilfish and Pearl Eartheater?

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
Pearl Eartheater
Test both in my tank

Behaviour & Temperament

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

Beckford's Pencilfish and Pearl Eartheater 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.

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

To improve the chances of a peaceful coexistence in this community tank: Provide a significantly larger tank (at least 50% more volume than the minimum) to allow both Beckford's Pencilfish and Pearl Eartheater to establish separate territories. Add plenty of line-of-sight breaks using driftwood, rocks, and dense planting to reduce territorial confrontations. A larger aquarium with ample hiding spots can help diffuse aggression and give the less dominant fish space to retreat.

Water Parameters

The safe temperature window for both species falls between 22°C and 28°C. Aim for the midpoint of this range (around 25.0°C) for optimal comfort.

Both fish can tolerate a pH between 6 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 5–15 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Beckford's Pencilfish and Pearl Eartheater together, plan for an aquarium of at least 250 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.

Because this pairing requires extra vigilance, include plenty of hiding spots — caves, driftwood, and dense plant clusters — so the less dominant fish can retreat when needed.

Specific environmental needs for this combination include: Plants - Densely covered, Plants - Floating, Leaf Litter/Blackwater, Sand (Sifters), Driftwood (Digestion/Hiding), Smooth Gravel (Sensitive Barbels). Meeting these requirements will help both species thrive.

Note a potential conflict in setup requirements: Pearl Eartheater is a plant destroyer, which conflicts with Beckford's Pencilfish's requirement for live plants. Compromise where possible or prioritise the more critical need.

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 Needs Extra Planning in Practice

This pairing usually fails when the tank is treated like a standard mixed community and the caution flags are ignored. Beckford's Pencilfish and Pearl Eartheater need extra room, more cover, and closer observation during the first few weeks so small aggression, feeding, or territory issues do not snowball into a long-term problem.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Beckford's Pencilfish and Pearl Eartheater.

Show 1 more tank size

Frequently Asked Questions

Can Beckford's Pencilfish and Pearl Eartheater live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 250 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Beckford's Pencilfish and Pearl Eartheater need?

A minimum of 250 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 Pearl Eartheater together?

Keep the aquarium between 22°C and 28°C. A target of around 25.0°C sits comfortably within both species' preferred ranges.

Are Beckford's Pencilfish or Pearl Eartheater aggressive?

Beckford's Pencilfish is peaceful (2/10) and Pearl Eartheater 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 Pearl Eartheater need?

Both species overlap in the 6–7.5 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

How do I manage Pearl Eartheater's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Pearl Eartheater 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 11, 2026
Last updated
May 11, 2026
Issues or corrections?
Contact the editorial team

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