Could My New Tank Have Cycled Already?

[GavinB]

ok, I have my new 180l tank and it was filled with water just 12 days ago. the substrate is gravel and was bought brand new. I placed a rock from the old tank (well established) into the new tank rather than transferring the media (as the fish are still living in the old tank)

I tested over the first 4 days and showed little to no change in ammonia or nitrites.

on the 6th day I showed a spike in Nitrites which continued for around 2 days.

on the 9th day I showed a small spike in ammonia.

now im showing literally 0 on both counts, No ammonia and no nitrites although the ph is rather high (this is just due to good old Hull city centre water which is harder than Chuck Norris in a fight against Mr T)

Could my tank really be cycled this quickly? Im going to guess its down to the large rock which I transferred but how much bacteria could it possibly transfer to cycle a tank of 180l that quickly!?

 

[GavinB]

Oh. There are 4 Zebra Danios in the tank (not fishless cycle)

 

[Wills]

The filter will most likley have caught up with the waste produced by the danios that are in the tank so yes kind of cycled but each time you add fish it will take a little while for the filter to catch up with the waste of the other fish.

Wills

 

[OldMan47]

You have achieved a very fragile balance, in my mind. You have a filter showing almost perfect conditions after a very few days. That means one of two things here. You either have something about your cycle that you are not telling us, or maybe you have a filter that is ready to take on anything you are ready to throw at the filter. So where are you? My best guess is that you have achieved a state where your partly cycled filter is ready. It is ready to take on minimal stocking levels, but is not yet ready for full stocking levels in your tank.