How did you originally cycle your tank? Maybe it wasnt done, that can cause some issues.
I am in the process of setting up a qt now for my 125g, I recently lost 6 fish die to NOT qt'ing so I highly suggest it.
Do you have an API saltwater liquid test kit? thats pretty much a necessity.
As far as the clowns I would wait til you can get your parameters set and everything else perfect. I have never used vodka in my tank, I find with proper water changes and basic maintenance you can get to 0 nitrates as well without adding anything.