Moderate

Black Ghost Knifefish

By The Aquarium Calculators Editorial Team ·

Apteronotus albifrons

Complete Black Ghost Knifefish care guide covering carnivore diet requirements, peaceful temperament, minimum 55 Gallons tank setup, and compatible freshwater tankmates. Difficulty: Moderate.

Black Ghost Knifefish

Quick Answer

Black Ghost Knifefish (Apteronotus albifrons) is a striking, nocturnal fish from South America. It requires a minimum 55 Gallons aquarium with a pH of 6.5 - 7.5 and temperature range of 24-28°C. This carnivore occupies the bottom zone and makes an excellent addition to community setups.

Intro

Black Ghost Knifefish (Apteronotus albifrons) is a striking, nocturnal fish from South America. It navigates and communicates using a weak electrical field.

Setup

A 55-gallon or larger tank with smooth rocks, driftwood, PVC pipes (hiding spots), and dim lighting. No sharp decorations. Moderate to strong filtration but gentle flow.

Feeding

Carnivorous; prefers live/frozen foods: bloodworms, blackworms, brine shrimp, and sinking meaty pellets. Feed after lights out.

Compatibility

Peaceful but territorial with its own kind. Keep singly. Tankmates must be peaceful and not fin-nippers: angelfish, Severums, larger tetras, Corydoras.

Aquarium Tank Volume Calculator

Enter your details below for an instant recommendation.

Recommended Output

Gallons

--

Liters

--

Empty weight

--

Filled weight

--

Tank Position
Bottom
Water Temp
24-28°C
Adult Size
See profile
Water pH
6.5 - 7.5

Species Characteristics

Adult Size
Lifespan
Growth Rate
moderate
Tank Compatibility
Community compatible
Indoor Aquarium
Yes

Water Parameters

Water Temperature
Humidity
Water pH

Tank Lighting

Tank Lighting
Standard lighting
Light Hours
N/A
Intensity
moderate

Feeding & Diet

Diet Type
Diet: Carnivore
Feeding Schedule
N/A
Live Food Options
N/A

Continue Learning

Recommended Tools

Fish Compatibility Calculator fish compatibility

Health & Disease

Ich (White Spot Disease) common disease • all fish

Related Guides

Understanding pH in Aquariums water parameters • ph

Similar Species

African Leaf Fish Care Guide: Diet & Tank Mates semanticSimilarity Angelfish Care Guide: Tank Size & Diet | The Aquarium Calculators semanticSimilarity Badis Care Guide: Tank Size & Compatibility semanticSimilarity

Frequently Asked Questions

How many Black Ghost Knifefish can be kept together?
Keep strictly one per tank, even in systems over 150 gallons (568 liters). Black ghost knifefish (Apteronotus albifrons) use weak electrical signals to navigate and become highly aggressive toward conspecifics, leading to severe bites, lateral line erosion, and death. A tank of at least 100 gallons (378 liters) with a footprint of 60x18 inches (150x45 cm) is required for a single adult (up to 20 inches/50 cm). Provide 4-5 PVC tubes and driftwood caves as refuges. Community tanks: Combine with peaceful large species (severums, geophagus) but never other knifefish.
What are the exact water parameters for Black Ghost Knifefish?
Target pH 6.5 - 7.5, General Hardness 4 - 10 dGH, Carbonate Hardness 3 - 8 dKH, Total Dissolved Solids 80 - 200 ppm, Electrical Conductivity 150 - 400 μS/cm, and temperature 73°F - 80°F (23°C - 27°C). They are scaleless fish highly sensitive to poor water quality; maintain nitrates below 10 ppm with weekly 30% water changes. Use a canister filter rated for twice the tank volume with minimal flow (max 500 GPH). Add driftwood and clay caves. Avoid any copper-based medications, which are lethal. Use reverse osmosis water mixed with tap to achieve stable TDS.
What is the dietary and medication protocol for Black Ghost Knifefish?
They are strict nocturnal carnivores. Feed exclusively live or frozen foods: bloodworms, blackworms, krill, chopped earthworms, and ghost shrimp. Offer food after lights out (use a red light) daily. They refuse dry pellets or flakes and will starve within 3 weeks. Supplement with frozen silversides. Medication alert: Extremely sensitive to copper (0.05 mg/L lethal), formalin, and malachite green. Use praziquantel (2 mg/L) for internal parasites. Never add salt (0 ppt). Treat with metronidazole at half-dose in food. Quarantine for 30 days.
How to breed Black Ghost Knifefish in captivity?
Breeding is extremely rare in home aquariums. To attempt, condition a group of 5+ juveniles in 200+ gallons (750 liters) with live foods for 6 months. Simulate dry season: Lower water level to 12 inches (30 cm) for 3 weeks, increase temperature to 80°F (27°C). Trigger rainy season: Raise water level to 24 inches (60 cm) with cool (68°F/20°C) RO water (pH 6.8, 2 dGH) over 12 hours. They are egg-scatterers; provide spawning mops and fine-leaf plants. Spawning occurs at night; 500-1000 eggs hatch in 72 hours. Fry require green water (Nannochloropsis) for 10 days, then baby brine shrimp.

Related Content

fish

African Butterflyfish

Complete African Butterflyfish care guide covering carnivore diet requirements, semi-aggressive temperament, minimum 30 Gallons tank setup, and compatible freshwater tankmates. Difficulty: Advanced.

fish

African Cichlid

Complete African Cichlid care guide covering omnivore diet requirements, aggressive temperament, minimum 55 Gallons tank setup, and compatible freshwater tankmates. Difficulty: Advanced.

fish

African Leaf Fish

Complete African Leaf Fish care guide covering carnivore diet requirements, semi-aggressive temperament, minimum 55 Gallons tank setup, and compatible freshwater tankmates. Difficulty: Moderate.

fish

African Red Eyed Tetra

Complete African Red Eyed Tetra care guide covering omnivore diet requirements, peaceful temperament, minimum 30 Gallons tank setup, and compatible freshwater tankmates. Difficulty: Easy.

fish

Angelfish

Complete Angelfish care guide covering omnivore diet requirements, semi-aggressive temperament, minimum 30 Gallons tank setup, and compatible freshwater tankmates. Difficulty: Moderate.

fish

Apistogramma

Complete Apistogramma care guide covering omnivore diet requirements, peaceful temperament, minimum 20 Gallons tank setup, and compatible freshwater tankmates. Difficulty: Easy.