Aquarium maintenance and water care guide

01

What this aquarium care guide covers

Freshwater fish rarely die from one dramatic event. Most problems build up slowly: ammonia in a tank that was never cycled, nitrate climbing between skipped water changes, a pH that drifts, or a heater that fails quietly. The pages in this section cover the routine side of fishkeeping, the part that prevents most diseases before they start.

Each guide gives clear numbers (percentages, ppm, °F and °C) and a step-by-step method, plus the common mistakes and the point at which you should stop and investigate further.

02

Start here if your tank is new

The first month decides a lot. Before buying fish, learn how to cycle a fish tank: it explains the nitrogen cycle, fishless and fish-in methods and how to read your test results. If fish are already in a new tank and getting sick, read about new tank syndrome right away.

When the tank is ready, acclimate new fish properly so the change in temperature and chemistry does not shock them. Our beginner aquarium guide puts all of these steps in order, from choosing the tank to the first fish.

03

Weekly fish tank maintenance

Once a tank is running, routine care takes 20–40 minutes a week for most setups. Our step-by-step guide on how to clean a fish tank covers glass, gravel, decor and the filter without disturbing the bacteria. For the most important single task, see our guide to the aquarium water change: how much, how often and how to treat the new water.

• Every week: 20–30% water change, gravel vacuum, glass, nitrate test
• Every 2–4 weeks: rinse filter media in removed tank water
• Every month: test pH, KH and GH, clean decor and lid

04

Water chemistry made simple

You do not need a chemistry degree, only a few target ranges and a reliable test kit. Start with our overview of aquarium water parameters, then go deeper where you need it: how to lower nitrates, how to lower pH or raise pH, and the right fish tank temperature for tropical and coldwater fish.

Change one variable at a time and slowly. A stable pH slightly outside the textbook range is safer than a perfect number reached by daily swings.

05

Feeding and everyday care

Overfeeding is the most common way beginners pollute their water. Our guide on how often to feed aquarium fish gives portions and schedules by fish type. For gentle extras, read about Indian almond leaves for blackwater fish and the right and wrong uses of aquarium salt.

06

Tools that make maintenance easier

Three items cover most routine care: a liquid test kit, a water conditioner and a gravel vacuum. Compare models in our guides to the best aquarium test kit, the best water conditioner and the best gravel vacuum. If something goes wrong despite good care, our troubleshooting hub covers diseases, algae and cloudy water.