Your first fish should survive your learning curve. Beginners inevitably make water-quality mistakes, so the smart move is choosing species that tolerate a wider range of conditions and stay peaceful in a community tank.

Seven forgiving choices - Zebra danios: active, cheap, and nearly bulletproof. They handle cooler water and temperature swings better than most. - Platies: colorful livebearers that are hardy and endlessly available. Just expect babies if you keep both sexes. - Corydoras catfish: charming bottom dwellers that clean up leftover food. Keep them in groups of six or more. - Harlequin rasboras: small, shimmering schoolers that stay calm and colorful. - White cloud mountain minnows: tolerant of cool, unheated tanks and very peaceful. - Cherry barbs: less nippy than other barbs, with males turning a deep red. - Bristlenose plecos: an algae eater that actually stays a reasonable size, unlike the common pleco that outgrows most tanks.

Stock slowly and in groups Add a few fish at a time so your filter bacteria can keep pace with the extra waste. Most of these species are shoaling fish, meaning they feel safe and behave naturally only in groups. A lone schooling fish is a stressed schooling fish.

Mind the tank size Even hardy fish need room. A 20-gallon tank gives you far more stability than a 5-gallon, because a larger water volume dilutes mistakes and resists rapid temperature change. Match adult size, not the tiny size you buy them at, to your tank. Many beginner heartbreaks come from a cute inch-long fish that grows into a foot-long tank-buster.