Looks all grey and unhealthy to me. Its definitely stressed about something.
My suggestions:
1. Double check those water parameters and post them if you would, this should include alkalinity, calcium, temp and pH ave. I would immediately suspect a nitrate problem as I see evidence of problematic algae in the pic. I would also suspect that is a result of having crushed coral substrate. If necessary have LFS test as well and compare that to your own results.
2. Crushed coral is sharp and may be causing the anemone some stress as well, I might place it on a rock if it were a BTA or sebae, most of the other types of anemone prefer to plant there foot into a sand substrate. I'd switch to sand.
I can't tell what type of anemone this is from the pic, what was he sold to you as?
I have a strong feeling that it is your water parameters
Thomas