Aquarium setup for beginners: the nitrogen cycle
The main reason new fish die is the nitrogen cycle. Build a healthy tank step by step.
The cycle
Fish waste produces toxic ammonia; filter bacteria convert it to nitrite and then nitrate, removed by weekly water changes.
Setup
Place the tank, add dechlorinated water, run the filter and heater, start the cycle and test until ammonia and nitrite read zero (3–6 weeks). Add fish gradually. Rinse filter media in tank water, never tap water.
Related breeds
Goldfish
The Nowruz fish—actually needs a large filtered tank and can live 10+ years.
Koi
Ornamental Japanese carp for large ponds, valued for colour patterns.
Guppy
A colourful livebearer—ideal for beginners and breeds readily.
Betta (Siamese fighting fish)
Long-finned and vivid; males must be kept alone.
Related articles
Keeping pets safe in summer heat
Heatstroke can kill in minutes. Signs, first aid and prevention for all pets.
Travelling with pets by car, plane and train
From carriers to motion sickness—everything for a calm trip with your dog or cat.
Rabbit care: 7 myths and real needs
Rabbits don’t live on carrots and need more than a small cage. Learn their real needs.