Laird-and-Dad
Aquarium Advice Freak
Yeah, it could be fluctuations in the tap.
The interesting thing is that your tank appears to be cycling again which seems quite strange.
That's what I thought, but even when I was doing my first - fish in - cycle I never got trItes that high. Even the ammo is higher than I've seen.
I added the baking soda like PNW said.