How to read it
A new tank has no bacteria to break down fish waste. Cycling grows them before any fish go in. It usually takes four to six weeks.
- Ammonia builds. You add ammonia and it stays, because nothing eats it yet.
- Nitrite spikes. The first bacteria turn ammonia into nitrite, which is also toxic.
- Nitrate appears. A second group of bacteria turns nitrite into nitrate, which is far less harmful.
The tank is cycled when it can turn about 2 ppm of ammonia into zero ammonia and zero nitrite within 24 hours. Tick "Dosed 2 ppm the day before" on the reading where you ran that test.
Your readings are saved in this browser only. Read the full guide: Cycle your tank before you add fish.