Cycling questions!

[EdsonFOWLR]

I have been cycling my new 122 Gallon FOWLR with a 60 Gallon sump for a month now. The ammonia is 0, the nitrates are in the 110 range and the nitrites are 1.0-1.6 range. My question is how long should it take to finish this last bit of nitrites into nitrates? Also is there anything I should be doing to help my cycle? The tank has 95lbs of live sand 80lbs of dryrock and 20lbs of liverock, as well I have been dosing the tank each day with stability. So far the cycle has been going good, ammonia went up then down, same with the nitrites but the seem to be stuck. I also will be adding a bubble king mag 5 skimmer to the sump, but don't know if I should add it while the tank is cycling or not.