I was pretty sure my tank has been cycled for the last two days. I dosed to 4ppm ammonia yesterday morning and checked it again this morning. Ammonia/nitrites were zero. Nitrates 20
So today I do a 40% water change to drop the nitrates. After I did the pwc
, I checked the levels again. Ammonia was zero, but Nitrites were around 4ppm?!! I doubled checked and got the same result
I checked the remaining salt water I had bought from the lfs
and it was zero nitrites.
What could have happene in the 8 hours I checked it this morning?!!