In the order you need them
Straight answers on tanks, cycling, and what fish you can actually keep — written for people setting up their very first aquarium.
These guides follow the order you actually need them in: choosing a tank and working out what it really costs, the equipment that matters (filter, heater, light, substrate) and what you can skip, the nitrogen cycle and how to run a fishless cycle properly, then stocking — beginner-friendly fish, easy live plants — and the maintenance routine that keeps it all stable.
Every guide is written by a named human author who keeps tanks, gives you the numbers to test against rather than vague advice, and gets updated when better information turns up. Read more about our editorial standards.
Can you use distilled water in a fish tank? Not by itself — it has no minerals and cannot hold a stable pH. Use it for top-offs and to soften hard tap water.
Do not fill a fish tank with distilled water alone. It has no minerals for the fish and no carbonate to hold the pH steady. Use it to top off evaporation and to dilute hard tap water, and use dechlorinated tap water for everything else.
Ammonia, nitrite and nitrate in plain English — how to run a fishless cycle step by step, and the one test that tells you the tank is ready for fish.
Run a fishless cycle with bottled ammonia for three to six weeks. The tank is ready when a dose of 2 ppm ammonia reads 0 ammonia and 0 nitrite within 24 hours — not before.
