Stopping stn

[Proteus]

I know there info on this. I know there's current threads. Ive tried the info on the net. And I don't want to hijack a thread

The story starts with a buddy's tank who runs or ran a successful sps zeo tank. He called me a few months back because his alk doser had been unplugged for whatever reason. His alk dropped to 5ish and began stn. He corrected the alk over a period of time as not to raise to fast. A while later while still battling stn he found that a zeo reactor had stopped working. For how long we don't know.

I took what I could for coral as he was going on holiday. I cut off the dead and fragged well into the healthy flesh. I dipped in RPS and put into tank. I do weekly WC. My params are excellent and none of my sps are affected. But still can't stop the stn.

Any suggestions