Your water parameters look perfectly fine to me to house a torch coral. One thing you may have overlooked is light or flow acclimation of the particular specimen.
Was this the only new coral you have added in the last week ..maybe a little more info over your tank .. how old is it ? What do you have in your tank ? Fish corals ? Acclimation ? The more info you can give ,the better !
I had bought a torch coral frag to add to my tank. Within a week it melted away. Then my other 2 torches that ive had for a year melted away within a week. Some sort of disease. Brown jelly?
I found spot feeding works better than broadcast feeding, the reason am suggesting this, is your system parameter are pretty much on and there may have been a possibility the the coral just starved.
Thanks alot guys!....just getting back into R2R after a few months of worldy problems. As for the tank....corals seem to be growing. The torch? I honestly have no idea what happened to it, but that seems to be the way it goes sometimes in this hobby. Spot feeding and dosing now started and on a much tighter schedule. Will see what happens with my little Euphyllia [emoji375]