A couple of things I can help you with ComeFullCycle. First you need to check that you have no nitrates in your tap water?
If the tap water has no nitrates then the rest will make sense.
One can’t have the bacteria that poop nitrates with the bacteria that poop nitrites. Don’t worry about never seeing any nitrites in a test as it’s all being eaten.You should never see nitrites again.
is to high for ammonia, I believe it stalls the cycle before it’s that high? I don’t remember I think it’s 4 ppm
as a maximum?A partial water change will lower the ammonia.
Adding another filter will only provide more possible homes for bacteria. But in truth each tank only needs enough bacteria for the daily poop load.On it’s own a new filter does nothing.