Can Lionfish and Red Eye Tetra Live Together?

Lionfish and Red Eye Tetra Compatibility Overview

Lionfish and Red Eye Tetra are generally not recommended to be housed together. One of these is a marine species and the other is not; they cannot share one aquarium. The adult size gap creates a meaningful predation risk. Review the behavior and water details before deciding whether to attempt the pairing.

Compatibility factors for Lionfish and Red Eye Tetra
Factor	Lionfish	Red Eye Tetra	Verdict
Temperature	72–82°F	72–79°F	✅ 72–79°F
pH Range	8.1–8.4	6.0–8.0	❌ No overlap
Temperament	aggressive	semi	❌ Risk
Adult Size	15.0 in	2.8 in	❌ 5× difference
Min. Group	1+	6+	See below
Min. Tank Size	100 gallons (for both species)		—

Compatibility Positives

A stable shared temperature range is available.

Incompatibility Reasons

One of these is a marine species and the other is not; they cannot share one aquarium.

The adult size gap creates a meaningful predation risk.

Their pH ranges do not meet: Lionfish wants 8.1–8.4 and Red Eye Tetra wants 6.0–8.0.

Lionfish is aggressive and Red Eye Tetra is semi. Expect chasing and fin damage unless the tank is oversized, heavily planted, and watched closely.

Species Profiles

Lionfish — Pterois volitans

Lionfish and Red Eye Tetra compatibility — Lionfish

Lionfish are popular saltwater aquarium fish known for their striking colors and intimidating spines. These fish require a large tank and careful attention to water parameters. Aggressive by nature, they can be harmful to smaller fish and invertebrates.

→ Full Lionfish care guide

Red Eye Tetra — Moenkhausia sanctaefilomenae

Lionfish and Red Eye Tetra compatibility — Red Eye Tetra

The Red Eye Tetra is a popular freshwater fish known for its vibrant red eyes and sleek, silver body. They are generally peaceful and can be kept in a community tank with other non-aggressive species. Their moderate activity level makes them suitable for a variety of aquarium setups. With proper care, they can live up to 5 years.

→ Full Red Eye Tetra care guide

Frequently Asked Questions

Can Lionfish live with Red Eye Tetra?

Generally not recommended. Lionfish and Red Eye Tetra are generally not recommended to be housed together. One of these is a marine species and the other is not; they cannot share one aquarium. The adult size gap creates a meaningful predation risk. Review the behavior and water details before deciding whether to attempt the pairing.

What tank size do I need for Lionfish and Red Eye Tetra together?

A minimum of 100 gallons is recommended for keeping Lionfish and Red Eye Tetra together. A larger tank improves water stability and reduces territorial conflict.

What temperature suits both Lionfish and Red Eye Tetra?

72–79°F — inside Lionfish's 72–82°F and Red Eye Tetra's 72–79°F.

Is a Lionfish aggressive toward a Red Eye Tetra?

The adult size gap creates a meaningful predation risk.

Related Compatibility Guides

Tank Size for Lionfish and Red Eye Tetra

Use the scenario that matches the actual group sizes and temperament you plan to keep.

Scenario	Tank	When it applies
Minimum viable	120 gal	Only for the recommended minimum groups, mature filtration, and close monitoring.
Recommended community	180 gal	Adds territory, swimming room, and a safer buffer for behavior.
Low-conflict setup	220 gal	Best when keeping larger schools or reducing territorial pressure.

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