So, what do you think caused this mass death?
it could of been anything including stress of the move, a small cycle, salinity swing, temp swings who knows....
Ugh! So many lost SPS. It's just heartbreaking to see. I'm so sorry it didn't go as planned. Any remaining life, hang onto it. Remember you only need a few polyps to start again, and these will grow into colonies again.
It really does suck, i think today im going to place my rocks how i want them and then sort through all the "dead" SPS and clip off any surviving parts, i dont have frag plugs but i have live rock sheets i cut with a bandsaw which will do for now
Don't get too ambitious. When I have a coral decline, I tend to leave it alone so whatever still remains will have a fighting chance. I think manhandling, cutting and mounting corals in delicate / declining condition seals their fate. You can always cut out the good part later when it has stabilized. I had a nice colony of one SPS, and 99.8% of it died. One solitary dot of life remained, and I left the piece in my tank. That dot now has three polyps, and when it is a little bigger I'll get in there and retrieve it.
well today i added more sand rather than spread it i decided to leave the rocks alone....for now, i also pulled out any dead coral but left any which were still hanging on. my refractometer is reading 1.005 on fresh RODI here, im not sure if got bumped during transport but the adjustor screw is rusted stuck so i decided to play it safe and adjust my salinity somewhere arounf 1.023 which gives me a little wiggle room till i can get a new one, other than that the water is looking good sofar, just added a bit more bio pellets to compensate for the increase in water volume, i need to get my mag 5 hooked up to that reactor to replace the maxi900
It sounds like you are doing all you can for the time being. Testing frequently is best.