I was having similar problems with my tank about 5 months ago Raymond...corals weren't really dying but things just weren't on point in my tank. That's when I went back to basics and got rid of the gfo and the bp and now just do water changes and dose 2part and my tank is doing great finally. Not saying that everyone should ditch their bp and gfo, but it's a suggestion that if all else fails, go back to the fundamentals of the hobby. Good luck and I hope your issues get resolved.
BTW, I removed the bp, gfo, ac and ls all within a matter of like a couple of days and there were no issues as a result of that.