Ok here are my preliminary thoughts.
You have a tank that is not cycled. That is sure in my mind. A cycled tank will not show NO2
. It can be toxic at levels above. 25 ppm
. It will be consumed and converted as waste into NO3
is only removed by doing regular water changes or heavily planted tanks. Nitrates (NO3
) can become dangerous to fish at arguably 40 ppm
These two things, nitrites and nitrates, (NO2
), are waste by products of bacteria that consume ammonia. Ammonia is introduced to your tank by fish poop and uneaten food. It could also be introduced by dead and decaying plants or even fish. Any amount of NH3
(ammonia) could be deadly. This is a general statement. There are exceptions but as I am not a scientific professional, I will not try to speak on that here.
Your test strips doesnt test for NH3
. So I will have to assume there is ammonia present in your tank.
There is an article on here on how to cycle with fish. In my signature is an article written by a member here on fishless cycling.