Skip to main content
4848OneShop

🔥 ZakGT: Buy today with special price — limited stock!

Fish Compatibility Master Guide

Who lives with who? — color-coded chart for 7 popular species

Stop guessing which fish can share your tank. Our expert-tested matrix covers betta, guppy, goldfish, tetra, cichlid, flowerhorn, and arowana — with detailed notes on why each pairing works or fails.

📊 49 species pairings❓ 10 expert FAQs🔬 Research-backed
By ZakGT Aquatics TeamPublished Updated

Legend

Compatible
Conditional
Risky
Not compatible

Compatibility Matrix

Read across rows: "If I have a {Row}, can I add a {Column}?". Hover any cell for the reason.

Have ↓ / Add →
Betta
Guppy
Goldfish
Tetra
Cichlid
Flowerhorn
Arowana
Betta
Aggressive (males); semi-aggressive (females)
Guppy
Peaceful, active schooling
Goldfish
Peaceful but messy (cold water)
Tetra
Peaceful schooling
Cichlid
Aggressive to very aggressive (varies)
Flowerhorn
Highly aggressive (kept solo)
Arowana
Surface predator, semi-aggressive

Detailed Pairings

Betta

Aggressive (males); semi-aggressive (females)

Full Betta care guide →
Betta + BettaNot compatible

Males fight to the death. Females sometimes ok in sorority of 5+ in 20gal+.

Betta + GuppyRisky

Bright male guppies trigger betta aggression. Female-only guppies in 10gal+ planted only.

Betta + GoldfishNot compatible

Different temperature (goldfish cold, betta tropical). Goldfish nip betta fins.

Betta + TetraConditional

Neon/ember tetras work in 15gal+ planted. Avoid fin-nippers (serpae, black skirt).

Betta + CichlidNot compatible

Cichlids too aggressive. Will kill betta or stress to death.

Betta + FlowerhornNot compatible

Flowerhorn will eat or murder betta within hours.

Betta + ArowanaNot compatible

Betta = prey size. Arowana eats anything that fits in its mouth.

Guppy

Peaceful, active schooling

Full Guppy care guide →
Guppy + BettaRisky

See betta row above.

Guppy + GuppyCompatible

Schools of 6+. 2 females per male prevents harassment.

Guppy + GoldfishNot compatible

Temperature mismatch plus goldfish eats guppies.

Guppy + TetraCompatible

Excellent community pair. Neon tetras with guppies is a classic combination.

Guppy + CichlidRisky

Only dwarf rams or apistogramma. Larger cichlids treat guppies as snacks.

Guppy + FlowerhornNot compatible

Guppies are flowerhorn food.

Guppy + ArowanaNot compatible

Same as betta — guppies are prey.

Goldfish

Peaceful but messy (cold water)

Full Goldfish care guide →
Goldfish + BettaNot compatible

See betta row above.

Goldfish + GuppyNot compatible

See guppy row above.

Goldfish + GoldfishCompatible

Same variety best (oranda with oranda, ranchu with ranchu). 20gal+ first fish, 10gal each additional.

Goldfish + TetraNot compatible

Temperature mismatch. Goldfish eat tetras.

Goldfish + CichlidNot compatible

Wrong temperature plus cichlid aggression.

Goldfish + FlowerhornNot compatible

Goldfish will be eaten or stressed to death.

Goldfish + ArowanaNot compatible

Wrong temperature plus prey size.

Tetra

Peaceful schooling

Full Tetra care guide →
Tetra + BettaConditional

See betta row above.

Tetra + GuppyCompatible

See guppy row above — classic community pair.

Tetra + GoldfishNot compatible

See goldfish row above.

Tetra + TetraCompatible

Mix species in schools of 6+ each. Avoid mixing fin-nippers with longfins.

Tetra + CichlidRisky

Dwarf cichlids only (rams, apisto). Larger cichlids eat tetras.

Tetra + FlowerhornNot compatible

Tetras are food.

Tetra + ArowanaNot compatible

Tetras are food.

Cichlid

Aggressive to very aggressive (varies)

Full Cichlid care guide →
Cichlid + BettaNot compatible

See betta row above.

Cichlid + GuppyRisky

See guppy row above.

Cichlid + GoldfishNot compatible

See goldfish row above.

Cichlid + TetraRisky

See tetra row above.

Cichlid + CichlidConditional

Same lake or region only (Africans with Africans, Americans with Americans). Overstocking reduces aggression in Mbuna.

Cichlid + FlowerhornNot compatible

Both are ultra-aggressive and will fight to death.

Cichlid + ArowanaRisky

Large cichlids (oscar, jaguar) can coexist with adult arowana in 200gal+.

Flowerhorn

Highly aggressive (kept solo)

Full Flowerhorn care guide →
Flowerhorn + BettaNot compatible

Flowerhorn eats betta.

Flowerhorn + GuppyNot compatible

Flowerhorn eats guppy.

Flowerhorn + GoldfishNot compatible

Wrong temperature plus flowerhorn eats goldfish.

Flowerhorn + TetraNot compatible

Tetras are food.

Flowerhorn + CichlidNot compatible

See cichlid row above.

Flowerhorn + FlowerhornNot compatible

Two flowerhorns equals one dead flowerhorn. Always solo.

Flowerhorn + ArowanaRisky

Possible in 250gal+ tank with intro from juvenile. High risk.

Arowana

Surface predator, semi-aggressive

Full Arowana care guide →
Arowana + BettaNot compatible

See betta row above.

Arowana + GuppyNot compatible

See guppy row above.

Arowana + GoldfishNot compatible

See goldfish row above.

Arowana + TetraNot compatible

See tetra row above.

Arowana + CichlidRisky

See cichlid row above.

Arowana + FlowerhornRisky

See flowerhorn row above.

Arowana + ArowanaRisky

Same-species groups only in 500gal+ with strong filtration. Solitary recommended.

Frequently Asked Questions

What fish can live with a betta?

Bettas can sometimes live with small peaceful schooling fish like neon tetras, ember tetras, corydoras catfish, kuhli loaches, and snails or shrimp (with risk). Avoid fin-nippers (tiger barbs, serpae tetras), bright or long-finned species that trigger aggression (male guppies, gouramis), and any fish that needs cold water (goldfish). Always 10 gallons minimum and heavily planted.

What fish can live with goldfish?

Goldfish are best kept with other goldfish of the same variety (oranda with oranda, ranchu with ranchu, fantail with fantail). Mixing fancy with single-tail goldfish leads to bullying. They can sometimes coexist with white cloud minnows, weather loaches (dojo loaches), and rosy barbs because all three tolerate cold water. Never with tropical fish — goldfish need 18-22°C while tropicals need 24-28°C.

Can male and female bettas live together?

Long-term cohabitation is risky. Males will kill females after breeding if not separated. Sororities of 5+ females in 20+ gallon heavily planted tanks can work but failure rate is 40-60%. Always have a backup tank ready for the loser.

What fish can live with cichlids?

Cichlids are best kept with same-region cichlids only. African Mbuna cichlids with other Mbuna, American cichlids with American cichlids. Bottom dwellers like Synodontis catfish (Africa) or plecos (America) can coexist if the tank is 75 gallons or larger. Never mix cichlids with timid fish — even dwarf cichlids will harass guppies and tetras.

Can guppies live with neon tetras?

Yes — this is one of the most popular community tank pairings. Both species prefer 24-26°C water, neutral pH (6.5-7.5), and gentle current. House guppies in 2 females per 1 male ratio (3+ males per female), neon tetras in schools of 6+. Minimum tank size 15 gallons.

What can live with a flowerhorn?

Flowerhorns are best kept solo. They are bred for aggression and will attack tank mates including their own kind. Some keepers have success with one Pleco (sailfin or common) as a tank-cleaner in 75+ gallon tanks, but the Pleco must be larger than the flowerhorn. Never put fish smaller than the flowerhorn — they will be eaten or killed.

How big does an arowana tank need to be?

Adult arowanas reach 24-36 inches. Minimum 75 gallons for juveniles under 12 inches, 200 gallons for adults, 500+ gallons for groups. Tank length matters more than depth — arowanas swim in long horizontal strokes. The tank must have a tight lid because arowanas jump.

Can you mix African and American cichlids?

No — mixing African and American cichlids is not recommended. African cichlids need hard alkaline water (pH 7.8-8.6, hardness 10-25 dGH) and American cichlids need soft acidic water (pH 6.0-7.5, hardness 4-12 dGH). Water chemistry alone makes long-term cohabitation harmful.

What is the most peaceful community fish?

For a peaceful community tank, consider neon tetras, harlequin rasboras, ember tetras, corydoras catfish, otocinclus, kuhli loaches, cherry barbs, and platies. All tolerate similar water parameters (24-26°C, pH 6.5-7.5) and rarely show aggression. A 20-gallon long tank can house 3 species of 6 each.

What fish should never be kept together?

Never combine: (1) Betta with male guppies — guppies trigger betta aggression. (2) Goldfish with tropical fish — temperature mismatch. (3) African with American cichlids — water chemistry conflict. (4) Flowerhorn with anything smaller — predation. (5) Arowana with small fish — arowanas eat anything bite-sized. (6) Two male bettas — guaranteed death.