Practical guide

Fishkeeping basics

Six lessons to read in order to start a freshwater tank, with diagrams, calculators and the source of every figure.

  1. The nitrogen cycle

    How an aquarium gets rid of its fish’s waste, and how to start a tank without putting them at risk.

    6 minRead

  2. Water parameters

    pH, GH, KH and CO₂: what these values measure, how to read your tap water report and choose fish that will thrive in it.

    5 minRead

  3. Temperature and equipment

    Choosing the tank, heater, filter and lighting, and understanding why warm water quickly runs short of oxygen.

    4 minRead

  4. Plants and hardscape

    Creating a layout with depth, choosing easy plants, planting them according to their type and getting through the first three months.

    4 minRead

  5. Routine maintenance

    A routine of a few minutes a day and half an hour a week: water changes, filter, tests and warning signs.

    3 minRead

  6. Welcoming and feeding your fish

    Choosing healthy, compatible fish, acclimatising them without shock, quarantining them and feeding them without polluting the water.

    4 minRead

Ready to plan your tank? The simulator checks the water, stocking and tankmates of your future selection.