Aquarium setup & care guides

Organized into lanes — the same five lanes a calm aquarium editor would use to walk a nervous beginner through their first year. Cycling first, then sizing and stocking, then the routine that keeps the tank stable.

Lane

Cycling & first setup

The first month. If you only read one lane before water goes in, read this one. Cycling is the step beginners most often skip — and the mistake that creates most new-tank emergencies. The setup guides below assume you'll cycle properly before adding fish.

Lane

Tank size & stocking

How many fish, how big a school, how big a tank. The inches-per-gallon rule that fish stores still quote is wrong — these guides replace it with bioload + behavior + tank-size minimums from FishBase and hobby consensus.

Lane

Water quality & maintenance

What the test kit is telling you, and what you do about it. pH, GH, KH, ammonia, nitrite, nitrate — the six numbers that decide whether a tank stays stable or whether you spend a weekend on emergency water changes.

Lane

Equipment

Filters, heaters, and air pumps. Buying guides ground every recommendation in manufacturer specs and known failure modes, with the math behind the spec. Sized for the tank in front of you, not generic buying advice.

Lane

Tank structure & safety

The boring guides that prevent the worst outcome. A tank seam failure or a glass crack dumps tens of gallons on a floor — these guides cover the engineering reasoning behind glass thickness, rim type, and load-bearing decisions.

Ask a FishTankMath question

Quick answers about aquarium math, how the calculators work, and common freshwater questions. Free, no signup. Not veterinary advice — for sick fish or tank emergencies, talk to an aquatic vet or your local fish store.

Hi, I'm the FishTankMath assistant. I answer questions about aquarium math (volume, water changes, stocking, dosing), how the calculators on this site work, and common freshwater-fishkeeping basics. I'm not a veterinarian — I can't diagnose or treat sick fish. For emergencies or sick livestock, talk to an aquatic vet or your local fish store.