[Son Of Skyline]

So half my acros have been suffering from RTN this past month. Some corals will lose branches suddenly, then the RTN will stop, then start again a couple weeks later...then stop again. Some corals are slowly receding from the base. Tips are dieing on others.

This coincides to two things I can think of. One, I started using this cheapo brand superglue gel for frags. Two, I stuck a moderately rusted wire cutter in my tank a couple times to cut some frags.

Could any of these two things cause what's happening? My water tests fine and I haven't made any changes to my setup.

TIA...