Had a mortality - Help save his tank mate

[AJ_77]

With added stresses of varying temps and salinity, your ailing chromis will have a hard time recovering as it is.

Add to the stresses a starvation diet (one feeding every three days), and it has even less of a chance. You'll read that these fish feed almost continuously in the wild, surfing the currents flowing over the reef.

I hope you can save it, but I don't know that you're getting the best advice from your LFS. There are some chromis-based threads on the board - have you searched them out? Lots of people have these fish.