Do I need to cycle my aquarium before adding fish?

Yes — cycling establishes beneficial bacteria that convert toxic ammonia to harmless compounds. The fishless cycle takes 4-6 weeks: add ammonia to the empty tank, test daily, and wait until the tank processes ammonia and nitrite to zero within 24 hours. Adding fish to an uncycled tank exposes them to toxic ammonia — the leading cause of beginner fish deaths.

How many fish can I put in a starter kit aquarium?

The old rule of one inch of fish per gallon is a rough guide at best. A 10-gallon tank comfortably houses 6-8 small fish like neon tetras or a single betta. A 15-gallon handles 10-12 small fish. Research each species' adult size and space requirements — many common fish grow much larger than pet store juveniles suggest.

Best Aquarium Starter Kits 2026