What this tool does

The Fish Compatibility Checker is an interactive tool that analyses whether different tropical fish species can live together peacefully in your aquarium. It takes your planned fish list, tank size, and setup details to identify potential problems before you buy your fish.

The tool produces a detailed compatibility report showing which fish pairs work well together and which combinations could lead to aggression, stress, or other serious issues in your tank.

When to use it

Use this tool when planning a new aquarium or considering adding fish to an existing tank. It is particularly valuable if you are combining species you have not kept together before, or if you want to avoid costly mistakes that could harm your fish.

The tool is also useful for troubleshooting existing tanks where you are experiencing unexplained fish deaths, aggression, or stress, as incompatible species may be the underlying cause.

How it works

You enter the fish species you want to keep, your tank size, and setup type. The tool then creates a compatibility matrix showing each species pairing with clear indicators for compatible, risky, or incompatible combinations. For problem pairings, it explains the specific conflict, whether that is territorial aggression, predation risk, or incompatible water requirements.

The tool also checks whether your tank is large enough for the total number of fish and suggests improvements like adding hiding spots or adjusting stocking levels. Nothing you enter is saved, and you do not need to create an account to use it.