Cichlid
What "cycling" actually means
Fish make waste, and that waste becomes ammonia, which is toxic even at low levels. In a healthy tank, beneficial bacteria living mostly in your filter turn ammonia into nitrite (also toxic), and other bacteria turn nitrite into nitrate, which is far less harmful and gets removed with regular water changes.
A brand new tank has almost none of these bacteria. "Cycling" is simply growing a big enough colony to handle the waste before your fish depend on it. Skipping it is the number one reason new keepers lose fish in the first month, often called new tank syndrome.
The fishless cycle, step by step
A fishless cycle is the kindest and most reliable method. No animals are exposed to ammonia while the bacteria grow.
- Set up and dechlorinate. Fill the tank, add dechlorinator, and run the filter and heater. Aim for about 78 to 82 F, which helps bacteria grow faster.
- Add an ammonia source. Dose bottled aquarium ammonia to about 2 ppm. Test after 15 minutes to confirm.
- Add bacteria (optional). A bottled nitrifying bacteria product or seeded media from a healthy tank can shorten the cycle a lot.
- Test every day or two. Track ammonia, nitrite and nitrate. When ammonia drops, nitrite rises. Then nitrite drops and nitrate rises.
- Keep feeding the bacteria. Each time ammonia hits 0, dose back to about 2 ppm. If nitrite climbs very high, a partial water change helps.
- Run the 24 hour test. The tank is cycled when it turns 2 ppm ammonia into 0 ammonia and 0 nitrite within 24 hours, with nitrate showing.
- Water change, then add fish. Do a large water change to bring nitrate down, then add your first fish. Stock gradually.
How long does it take?
Usually about 4 to 8 weeks. It can be faster with bottled bacteria, seeded filter media from an established tank, or warmer water. It can be slower with cold water, very soft water, or if chlorinated tap water is ever used to rinse the filter.
Reading your test results
| Stage | Ammonia | Nitrite | Nitrate |
|---|---|---|---|
| Week 1 to 2 | High | 0 to rising | 0 |
| Middle | Falling | High | Starting to show |
| Almost there | 0 within a day | Falling | Rising |
| Cycled | 0 | 0 | Present |
What about a fish-in cycle?
If you already have fish in an uncycled tank, do not panic. Test daily and do water changes whenever ammonia or nitrite climbs toward about 0.5 ppm. A water conditioner that binds ammonia, plus bottled bacteria, helps protect fish while the colony grows. Feed lightly and hold off on adding more fish.
Cichlid specific tips
- Cichlids are big eaters and big waste makers, so a strong, mature filter matters. Many keepers run two filters.
- For African cichlid tanks with a high pH, ammonia is more toxic, which is one more reason to fully cycle first.
- When stocking mbuna, many keepers add a group at once to spread aggression. Only do that in a fully cycled tank with strong filtration, and watch the readings closely that first week.
Frequently asked questions
How do I know my tank is cycled?
When it converts about 2 ppm of ammonia to 0 ammonia and 0 nitrite within 24 hours, and you see nitrate. Then do a big water change and start stocking.
Do bottled bacteria really work?
Many keepers find quality bottled nitrifying bacteria shorten the cycle. Keep testing to confirm rather than trusting the label alone.
Why is my new tank cloudy?
A milky haze in the first weeks is usually a harmless bacterial bloom. It tends to clear by itself. Avoid overfeeding and keep testing.
What you will need
- Liquid test kit (ammonia, nitrite, nitrate, pH)More accurate than strips. You will use it for years.Check price on Amazon
- Water conditionerRemoves chlorine and chloramine from tap water.Check price on Amazon
- Bottled nitrifying bacteriaGives the cycle a head start.Check price on Amazon
- Bottled aquarium ammoniaThe clean, measurable way to feed a fishless cycle.Check price on Amazon
- Adjustable heaterWarmer water speeds up the cycle.Check price on Amazon
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