Fishless cycling test results?

[Dano83]

Hello,

I set up my 5.5 gallon tank two weeks ago and i've been using 10% ammonia keeping it at 4ppm in the tank. The last few days the ammonia keeps dropping to zero and the nitrites are dropping a little bit each day. My question is is it normal for my nitrates to stay at 5.0 ppm although the nitrites are dropping?

 

[Colin_T]

Nitrate test kits will read nitrite as well. So if you have nitrite it will show up as nitrate too. If the nitrites are going down slowly, the nitrates should go up a little bit. However, because the nitrate test kit will be reading nitrite too, the combined nitrite & nitrate could sit on 5ppm for a while.
Basically as the nitrite comes down, the nitrate will be going up.
If you have 2ppm nitrite and 3ppm nitrate, it will read as 5ppm nitrate. A couple of days later the nitrite might drop to 1ppm and the nitrate could be 4ppm, this will still show up as 5ppm of nitrate.
Once the ammonia and nitrite come down to 0, the nitrates should start to go up more

If your ammonia is dropping to zero and the nitrite is coming down, then the filters are almost ready for fish