How To Cycle a New Aquarium Without Killing Your Fish, by Skills to leave the Mountain on YouTube. 22 min 54 s.
- Video length
- 22 min 54 s
- Time to do it
- 4 to 6 weeks
- Difficulty
- Medium
- Steps
- 8
What you need
Steps
Fill the tank with dechlorinated water, set up the filter and heater, and run them. Do not add fish yet.
Add a source of ammonia. Use a bottled ammonia product or a pinch of fish food, aiming for about 2 to 4 ppm ammonia on a test kit.
Test ammonia, nitrite and nitrate every day or every few days. Write down the readings so you can see changes.
When ammonia starts falling, test for nitrite. Keep the filter running and do not clean the filter media in tap water.
Keep adding a small ammonia dose when ammonia reads zero to feed the bacteria. Nitrite will rise, then fall as nitrate appears.
Once ammonia and nitrite both read zero, do a partial water change to bring nitrate down, usually to 20 to 40 ppm or lower.
Confirm the tank is cycled by dosing ammonia to about 2 ppm. If ammonia and nitrite return to zero within 24 hours, the filter is ready.
Add fish slowly, a few at a time, and test ammonia and nitrite every day for the first week. Feed lightly.
Tips and common mistakes
Do not use live fish to cycle a tank; fishless cycling avoids ammonia burns and stress.
Old tank water carries little bacteria; move filter media or gravel from a healthy tank instead.
Avoid replacing filter cartridges during cycling because that throws away the bacteria you are growing.
Keep power cords and sockets away from splashes and use a drip loop.
Questions
How long does aquarium cycling take?
Usually 4 to 6 weeks, but it can be faster with mature filter media and slower in cold water.
Can I use old aquarium water to speed it up?
No. Beneficial bacteria mostly live on filter media, gravel and tank surfaces, not in the water.
Do I need to cycle a planted tank?
Yes. Plants help use nitrate, but the filter still needs bacteria to process ammonia and nitrite.
This guide was drafted from the video's details and general task knowledge. It has not been checked against the full video. Check the video and relevant product instructions before following a procedure. Report a correction.
