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Aquarium Cycling Tracker

Track the nitrogen cycle and know when your tank is safe for fish.

Calculator

How it works

The nitrogen cycle: Ammonia → Nitrite → Nitrate. A tank is cycled when it can process a dose of ammonia to 0 ppm ammonia and 0 ppm nitrite within 24 hours, with nitrate present. Fishless cycling typically takes 3-6 weeks.

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Formula & Method

The nitrogen cycle: Ammonia → Nitrite → Nitrate. A tank is cycled when it can process a dose of ammonia to 0 ppm ammonia and 0 ppm nitrite within 24 hours, with nitrate present. Fishless cycling typically takes 3-6 weeks.

Example Calculation

Day 0 dose ammonia to 2-4 ppm; ammonia falls and nitrite rises (~week 2); nitrite then falls and nitrate appears (~week 4). When both ammonia and nitrite read 0 in 24h, the tank is cycled.

Frequently Asked Questions

How long does it take to cycle a tank?
A fishless cycle usually takes 3-6 weeks. Adding mature filter media or bacteria starters can speed it up significantly.
Can I add fish before cycling?
It's risky. A fish-in cycle stresses and can kill fish from ammonia and nitrite. Fishless cycling is safer and more humane.

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