How do I know if my fish are compatible?

Use the tankly.ai fish compatibility matrix to compare multiple species at once. The tool analyzes aggression levels, temperament, water requirements, fin-nipping risk, predation, and 50+ research-validated species rules to give you a compatibility score from 0 to 100.

Can bettas live with other fish?

Bettas can live with some peaceful species in larger tanks (10+ gallons). Good tankmates include Corydoras catfish, snails, and some rasbora species. Avoid fin-nippers like tiger barbs and other aggressive or long-finned fish.

What fish can live together in a community tank?

Good community fish include neon tetras, harlequin rasboras, corydoras catfish, guppies, platies, and bristlenose plecos. Always check compatibility before adding new fish. Consider aggression levels, size differences, and water parameter requirements.

Can cichlids live with other fish?

It depends on the cichlid species. Many are territorial and aggressive. African cichlids generally need species-specific setups. Some dwarf cichlids like rams can work in peaceful community tanks. Always verify with a compatibility checker first.

Fish Compatibility Checker — Can These Fish Live Together?

The Complete Fish Compatibility Guide

Building a community aquarium is one of the most rewarding parts of the fishkeeping hobby — but choosing the wrong tankmates can lead to stress, aggression, and even death. The tankly.ai fish compatibility matrix helps you make informed decisions before adding new fish to your tank.

How Our Compatibility Matrix Works

Our scoring engine analyzes multiple factors to determine if species can coexist peacefully:

Aggression Scoring: Each species is rated on a 1-10 aggression scale. Large mismatches between peaceful and aggressive species are flagged immediately.
Fin-Nipping Risk: Known fin-nippers (like tiger barbs) are flagged when paired with long-finned species (like bettas or angelfish).
Predation Risk: Larger predatory species that may eat smaller tankmates are identified and warned about.
Environment Matching: Freshwater, saltwater, brackish, and coldwater species are checked for compatibility. Mixing environments results in an automatic incompatible rating.
Zone Overlap: Fish occupying different water zones (top, mid, bottom) get a compatibility bonus for reduced territorial competition.
50+ Species-Specific Rules: Research-validated rules from SeriouslyFish, Reef2Reef, PufferForum, and experienced aquarists cover known dangerous pairings.

Tips for Building a Community Tank

Always research species before purchasing — impulse buys lead to compatibility problems.
Consider the adult size of fish, not their juvenile size at the store.
Maintain proper schooling numbers — many species need groups of 6+ to feel secure.
Provide adequate hiding spots with plants, rocks, and driftwood to reduce territorial aggression.
Match water parameter requirements — don't mix fish needing different pH, temperature, or hardness.
Introduce less aggressive species first, then add more assertive fish once territories are established.

Freshwater Community Tank Favorites

Some of the most popular and beginner-friendly community fish include neon tetras, corydoras catfish, cherry barbs, harlequin rasboras, platies, and bristlenose plecos. These species are generally peaceful, hardy, and adapt well to a variety of tank conditions.

Common Compatibility Mistakes

The most frequent mistakes new fishkeepers make include keeping bettas with fin-nippers, mixing African and South American cichlids, overcrowding tanks, and ignoring minimum group sizes for schooling fish. Our compatibility matrix helps you avoid all of these common pitfalls.

Frequently Asked Questions

How accurate is the fish compatibility matrix?

Our matrix uses a database of 120+ species profiles with scoring rules validated against SeriouslyFish, Reef2Reef, PufferForum, and hobbyist communities. However, individual fish temperament can vary — always monitor new tankmates closely after introduction.

Can I check saltwater fish compatibility?

Yes! Our database includes both freshwater and saltwater species including tangs, clownfish, wrasses, gobies, blennies, and more. The same compatibility principles apply.

Is the fish compatibility matrix free?

Yes, the web-based compatibility matrix is completely free to use. For advanced features like habitat tracking, water analytics, AI care plans, species scanning, and reminders, join the tankly.ai waitlist.

Fish Compatibility Matrix

Build Your Tank

Want AI-powered stocking advice?

Popular Pairings