Let it go. Wait until you see NH3
at zero before doing a water change. You can remove the shrimp in a few days if the smell gets to be too much. Once you see a large spike in NO3
with no detectable NH3
, you can do a large water change and monitor levels for another week. If all levels remain appropriate you are ready to go. Remember that you should add livestock very slowly at first. I would not worry about the skimmer yet. You can start using one if you want, it will not hurt anything...won't really help much either. Good luck!