Melting torch coral

[Coralgurl]

I have 2 torch corals, one neon green (in tank for a month) and one yellow tip (in tank for a week) and both seem to be melting. I've got one on the sand and one on the rocks. So far I've got 2 heads left on the green and 3 heads have melted on the yellow. I've also noticed my trumpet coral is starting to recede (was transferred from My 55). I've been dosing magnesium as it was at 1200 a few days ago and kh which was at 6. I've turned the power heads down to about 75%.

What else should I do?