Yes, if the biological filtration you already have is sufficient (already cycled), then it should easily convert 2 ppm
worth of ammonia into nitrates in 24 hours. You can take measurements in between, but there's no need to measure other than when you first put in the ammonia (to make sure it's at least 2 ppm
) and again at 24 hours to make sure you have 0 ammonia, 0 nitrites, and an increase in nitrates.
If not, then you are correct in that you want to go through the cycle, using the ammonia again. Every 24 hours you should add enough to get it up to 2 ppm
and test until you see what I talked about before after 24 hours: 0 ammonia, 0 nitrites.