Check adult requirements
Record the baseline and check the species’ natural social structure. Do not infer the aquarium's condition from a single sign. Confirm scientific identity, adult size, diet, social behaviour and swimming zone.
Then compare minimum number and sex ratio where relevant with livestock needs and recent changes. Look for genuine overlap in water, flow, territory and feeding throughout the year.
Assess compatibility and welfare
Adjust one variable and assess space to gather, withdraw and hold territory before continuing. Keep a reference so the result can be compared. Plan the complete group and monitor feeding, breathing, injury, shelter and space use.
Do not treat “minimum” as ideal when the aquarium supports a more functional group.