Bounce mushroom dying

[armreefer]

I have this bounce mushroom from December and it was fine,growing in a size. On March I moved tank (emptied rocks into plastic storage,drained water, but left sand in display). After moving tank it was stressed for couple days and then fully opened up for about a week and was totally normal and then it start to look stressed , mouth open, shrink in size.
Need help to save it. What can I do which dip can save it ?
All other corals look good.
Water parameters
Nitrates-7.4 ppm
Phosphate-0.07ppm
Alkalinity-8.9 Dkh
Calcium-400ppm
Magnesium-1230ppm

 

[Lost in the Sauce]

First thing id do is move it down to low light and low flow.