How do you add new fish to your tank safely? Plan the quarantine, float and first batch

Bringing new fish home is the riskiest hour of the year for your tank. Sick newcomers can spread illness, sudden water changes stress fish, and too many arrivals at once overload the filter.

This guide gives you a planner that builds a step-by-step arrival plan from your tank, then explains quarantine, floating the bag, and adding a few fish at a time. Sources differ on quarantine length, so we say so. Ask a fish vet if a fish looks unwell.