Yes, the masked swallow tail is becoming one of my favorite fish pretty quickly. The male is little aggressive toward the female. But I read that this is normal and you actually need this to have the color stay on the male. It chases the female if it comes too close but doesn't bite it. My lfs still have two female, I'm debating whether if I want to add another one to make it a trio.
I'm still a little skeptical on these for nipping my sps. I think I saw them doing it but I'm not really sure if they're the one causing the baldness of my acros. I know my Majestic is definitely not going in the new tank. It's a corals nipper! I love the fish but I love my acros more. I'm going to try to trap the Majestic out and watch how the acros response with the two swallow tail. If I see them nipping, then they're are out!
10% weekly water change is really all I do. GFO and carbon change out every month or so. I'm using BRS 3 parts dosing for my supplement. I may have to get a CA reactor on the bigger tank but will have the dosing running in conjunction with the reactor.