hope all goes well. If your sps are healthy, I think hardier species should be able to make it.
btw, did you change some water?
hope you dont mind, I want to learn from your experience.
months ago, I also nearly kill my sps by over dose Alk. at that time KH is more then 20.
I change almost 80% water and KH still 15. some sps rtn after the incident....