Fishless cycle help!!


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Hey y’all! I’m new here and decided to pop on to ask for help on my nitrogen cycle. I am about 6 weeks into the fishless cycle, and I have been using the API freshwater master test kit. I used Dr. Tim’s ammonia to start the cycle, and the ammonia was at 4 ppm to start, but it only ever decreased when I would do a water change, and the nitrite levels have increased to 1 ppm and back to 0 ppm as of today, and the nitrate levels increased from 0 ppm to 40 ppm over the course of the cycle. After doing a water change, the ammonia levels have been at 1 ppm for about 2 weeks now. I don’t understand how the ammonia doesn’t change but the nitrite and nitrate levels indicate that the cycle is complete. The test kit isn’t expired. My ph is 7.2, the temp is 82 degrees, I dechlorinate the water at every water change, and I have live plants. There is also about .50 ppm ammonia in my tap water already, but I figured the bacteria would still be able to consume it. Thanks to anyone who can help!


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4 years
There is two different types of beneficial bacteria for the nitrogen cycle. One consumes ammonia producing nitrite, the second consumes nitrite producing nitrate. The two bacteria colonies can and will exist together, but can colonize at different rates. It is more common for the first to colonize before the second and produce nitrite, but not exclusive. The second can colonize faster then the first consuming the nitrite producing nitrate, faster then the first can consume ammonia and produce nitrite. Or any combination of the three tests. So you can still read ammonia but no nitrite, and read nitrate. I know this is confusing, but I hope you get the idea.

Give your cycle a few more days, to settle down.

There is a third that consumes nitrate producing a harmless gas that bubbles away, but this is a different subject for a later date.

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