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TankTrue — aquarium cycle forecast & water log

When will my tank finish cycling?

Likely done

Updated with better evidence. See where our dates come from

You ticked "added bacteria". Which was it?

Start here

Your tank meets the cycled rule.

Tip: a liquid test kit is the surest double-check before adding fish, since strips can miss low levels.

What to do today

Recent tests

Your tank

Tanks

The side-by-side overview of every tank comes with Pro. Each tank's own warnings show free on its screen. See Pro.

This tank needs attention

Tools

Learn

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Today Tank Tools Learn

Send your cycle

Know when your tank is ready.

A finish date for your cycle, with an honest range, built from your own tests.

How big is it?

Where is it now?

When did you start?

What's feeding it?

Added bacteria or seeded media?

Your first test

Likely done

Cycled.

Log tests and water changes here to keep it that way.

Free ammonia uses Emerson et al. (1975). Cycle timing uses typical phase lengths adjusted for your temperature and pH, then your own nitrite trend once it's falling.