Hey, I am a little confused... My tank is now 3 weeks old, and seems to be fully cycled. I wasn't sure this was possible but I have been testing and testing the water with my API freshwater master test kit and the results have been steady.
This is what I did..
First 3 days no fish, no plants, just added substrate and rocks. the place I got the tank from suggested this new product called API quick start which is supposed to contain beneficial bacteria?? I have heard all sorts of mixed reviews on this stuff, but hey I used it.
Mid week I added around 10 live plants, various types. I have a 110L /29g Juwel Rekord tank. left the tank cycling fish less for one week. Took water to be tested at fish shop and was showing levels but they said it would be ok to add 6/7 hardy fish. I got 7 glow light tetras and took my time adding them to the tank, floated them for an hour adding an egg cup of tank water every 5 mins or so. they took to the tank within an hour or so and were very happy!
Around the middle of the 2nd week I noticed the nitrites spiked right up into the the danger zone (I only had a nitrite test then, so couldn't check the ammonia) so I did around a 15% water change, which brought the nitrite level right down from then on. that weekend I purchased the API master test kit and started testing all the parameters. they were all showing very low levels so at the end of the 2nd week I took more water to the fish shop for testing to see if we could add more fish.
Water was fine so I got 7 Danios, 5 leopard and 2 zebras and added them in the same way. They were round the tank as if they had always been there, absolutely insane fish!! so by the end of week 2 I had 14 fish in my tank.
Been keeping a very close eye on all levels this 3rd week as I couldn't believe I could have so many fish so quick, and I really don't want the fish to suffer etc, but to my astonishment I'm reading 0ppm ammonia, 0ppm nitrites and low levels of nitrate, but there is a reading. I am going to leave the tank a couple weeks now before adding any more fish, but from what the tests are showing it seems as if my tank has cycled??? and to be honest, it probably happened less than 3 weeks, more like 2 1/2 weeks? it sounds ridiculous I know, but if thats what the chemistry shows, it must be right?
The only other thing I used was API stress zyme + a few times, which is supposed to help the bacterial growth etc. I am a little skeptical about these products though, so who knows if they helped or not?? seems coincidental that the tank seems to be cycled after a couple weeks.
Read more: Three weeks into fishless cycle, no nitrites