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STATUS: INCOMPATIBLE ⬌ MATRIX CORRELATION INDEX

Can you keep Discus and Red Tailed Black Shark together?

Algorithmically generated environmental and behavioral compatibility report.

DiscusSymphysodon aequifasciatus
mid Layerpeaceful
✕
incompatible
Red Tailed Black SharkEpalzeorhynchos bicolor
bottom Layeraggressive
INCOMPATIBLE

Algorithmic Assessment

Water acidity (pH) parameters clash. Red Tailed Black Shark prefers a pH of 6.8-7.5, while Discus requires a pH of 5-6.5. There is no overlapping safe pH range.

Scientific Parameter Comparison

Cross-reference water chemistry, temperature range envelopes, and physical dimensions of Discus and Red Tailed Black Shark.

Parameter MetricDiscusRed Tailed Black SharkCalculated Overlap
Temperature Range82°F – 88°F72°F – 82°F82°F – 82°F
pH Chemistry5.0 – 6.56.8 – 7.5No Overlap (Mismatch: 0.3)
Min. Tank Capacity50 Gallons55 Gallons55 Gallons (Minimum)
Aquatic Strata ZonemidbottomSeparated Layers
Adult Size (Max)8.0" (20 cm)6.0" (15 cm)Ratio: 1 : 1.3

⚠ Physiological Mismatch Report

Our stocking engine calculations indicate that putting these two species in the same tank causes acute physiological strain. Below are the calculated parameters that violate safe cohabitation ranges:

Acidity/pH Gap0.3 pH difference

Discus thrives in pH 5-6.5, while Red Tailed Black Shark needs pH 6.8-7.5.

Behavioral & Environmental Compatibility

⚔️ Do Discus and Red Tailed Black Shark Fight?

Behavioral analysis indicates a severe compatibility clash. The Red Tailed Black Shark is known for highly territorial and aggressive behaviors. In a shared environment, it is highly likely to harass, injure, or stress the more peaceful Discus, making them completely incompatible cohabitants.

🍽️ Swimming Layers & Feeding Competition

To satisfy their dietary requirements, offer a varied feeding schedule. Sinking pellets or wafers are ideal for bottom dwellers, while floating flakes or micro-granules support mid and top dwellers. The Discus occupies the mid layer, while the Red Tailed Black Shark occupies the bottom layer. This separation of swimming zones naturally minimizes direct interactions and reduces competition during feeding times.

📏 Size Difference & Predation Threat

Both species are closely matched in physical dimensions, with Discus growing to 8.0 inches and Red Tailed Black Shark reaching 6.0 inches. This size balance ensures neither species holds a physical dominance advantage.

Safe Tankmate Alternatives for Discus

Since the pairing between Discus and Red Tailed Black Shark is flagged as incompatible, here are 3 peaceful community tankmates that share a flawless compatibility profile with Discus and match similar water parameters:

Discusmid Layer
Scientific NameSymphysodon aequifasciatus
Min Tank Capacity50G
Aggressionpeaceful
Temp Envelope82°F - 88°F
pH Chemistry5.0 - 6.5
Scientific NameEpalzeorhynchos bicolor
Min Tank Capacity55G
Aggressionaggressive
Temp Envelope72°F - 82°F
pH Chemistry6.8 - 7.5

Chemistry & Habitat Analysis

Temp Envelope
82°F - 82°F
Shared temperature bounds.
pH Chemistry
No Overlap
Acidity requirements clash.
Combined Min Tank
55 Gallons
Lowest acceptable volume.

Frequently Asked Questions

Are Discus and Red Tailed Black Shark good tank mates?

Water acidity (pH) parameters clash. Red Tailed Black Shark prefers a pH of 6.8-7.5, while Discus requires a pH of 5-6.5. There is no overlapping safe pH range.

Can you put Discus and Red Tailed Black Shark in the same tank together?

Behavioral analysis indicates a severe compatibility clash. The Red Tailed Black Shark is known for highly territorial and aggressive behaviors. In a shared environment, it is highly likely to harass, injure, or stress the more peaceful Discus, making them completely incompatible cohabitants.

What water temperature and pH parameters do Discus and Red Tailed Black Shark need?

Both species require compatible parameters. Discus needs a temperature of 82°F to 88°F and a pH of 5.0 to 6.5. Meanwhile, Red Tailed Black Shark needs a temperature of 72°F to 82°F and a pH of 6.8 to 7.5. Shared overlap range: 82°F–82°F temperature and No safe pH overlap overlap.

What is the minimum combined tank volume required to house Discus and Red Tailed Black Shark?

To successfully house both species together, a baseline of 55 gallons is required. However, because the setup includes territorial behavior from Red Tailed Black Shark (aggressive), we recommend an adjusted minimum tank volume of at least 75 gallons (adding a 20-gallon safety buffer) to establish separate visual boundaries and minimize stress.

Do Discus and Red Tailed Black Shark occupy the same swimming layer?

These species occupy different vertical zones. Discus prefers the mid layer, while Red Tailed Black Shark commands the bottom zone. This natural spatial stratification creates an effective biological barrier, preventing direct face-to-face boundary friction and reducing territorial encounters.