Fishful Thinking
Your tank, thought through.
Learn how to set up and care for a tank, research every species before you buy, and plan a setup where everyone gets along.
Research before you buy
Size, tank, water and temperament for every species, with care levels at a glance.
Meet today’s pick
A different species every day, straight from the encyclopedia.
New to fishkeeping?
Do these in order. Skipping the cycle is the most common reason new tanks lose fish.
Pick freshwater or saltwater
Freshwater costs less and forgives more. Saltwater needs salt mix, purified water and extra flow. Read how they compare.
Plan the whole setup
Choose a tank, filter, decor and fish together so everything fits. Not sure where to begin? Take the quiz, then Tank Theory checks it as you go.
Cycle the tank
Run the filter with an ammonia source for 4 to 8 weeks, until tests show 0 ammonia, 0 nitrite and some nitrate. How to cycle · Track it.
Add fish slowly
Start with a few hardy fish and add more every couple of weeks, so the bacteria can keep up. Adding fish.