Ok, so yesterday I got a cheap water test kit because it's all I can afford right now (it's the dipstick kind). It said that my nitrite level was in the "danger zone" so I did a 100% water change. The tank is 1.7, unfiltered, no live plants. Up until that point I was doing 70% weekly water changes for about 2 weeks (haven't had him for very long). I didn't rinse and lightly scrub everything in the tank like I usually do because I thought the nitrite level might be from me over-cleaning things. My 1 gallon bowl that houses my smaller fish had great water params when I also checked it yesterday. I checked them both again tonight and the 1 gallon bowl was still perfect but the 1.7 tank showed the nitrites in the "stress zone" area. How could the nitrites have risen to that level in just 24 hours? I understand what new tank syndrome is but I didn't think nitrites could skyrocket like that. The fish seems to be acting completely normal and isn't showing any signs of stress that I can see.
Someone please help me understand what is going on :/