Start where your tank is.
Water & Cycling
The nitrogen cycle, ammonia, nitrite, nitrate, water changes and dechlorinators.
Problems
Cloudy water, algae, disease and symptoms: cause, how to confirm it, fix, prevention.
Setup & Gear
Tanks, filters, heaters and the gear that actually matters for a 5 to 40 gallon tank.
Species
Care guides for small, popular freshwater fish, shrimp and snails.
Calculators
Fishless cycle dosing and water change planning, with the formulas on the page.
Every number has a source.
Temperatures, ammonia limits and dosing figures link to the agency, extension service or paper they come from. When a number is our own calculation or our inference, we say so.