What Fish Can I Keep Together?

Understanding Compatibility in Your Community Aquarium

Creating a peaceful and balanced community tank isn’t just about choosing your favorite fish—it requires careful planning and a solid understanding of fish compatibility. With thousands of freshwater species available, not all fish will get along. Compatibility issues can lead to stress, aggression, and even fatalities.

Pro Tip: Use Betterscape's TankBuddy Chat to simulate fish combinations and check compatibility before adding new species.

1. Match Water Parameters

Different species thrive in different environments. Combining incompatible water parameter needs leads to long-term stress.

African cichlids prefer hard, alkaline water.
South American species like tetras often need soft, acidic water.
Match temperature, pH, and hardness across all tank mates.

2. Size and Feeding Habits

If it fits in the mouth, it’s food. Large fish may eat smaller tankmates.

Keep small fish away from large predators.
Ensure bottom dwellers aren’t outcompeted at feeding time.

3. Temperament & Behavior

Aggression varies by species—and even individual personality.

Tiger barbs are notorious fin-nippers.
Bettas may clash with other long-finned or colorful fish.
Research schooling needs vs. solitary tendencies.

4. Use All Swimming Levels

A peaceful community tank utilizes all zones of the aquarium:

Top: Guppies, hatchetfish
Middle: Tetras, rasboras
Bottom: Corydoras, loaches

Tip: Building your tank around a peaceful centerpiece species like a gourami can simplify compatibility planning.

5. Always Have a Backup Plan

Fish have personalities. Even “peaceful” species can turn aggressive.

Observe new additions closely.
Be ready to rehome or isolate problematic fish.

🎯 Need help?
Upload your tank photo or plan at Betterscape.ai and let our AI recommend compatible tankmates tailored to your setup.