acans like higher alk, and like to be alone in a low flow moderate lighting location, if color looks like an issue usually lighting and, if not fluffing usually water param.
This does not look great at all - It looks as if there is recession of the tissue. Did it look like this when you bought it? Could you see skeleton when you bought it?
Acans are photosynthetic, but they also will take meaty foods if they are interested - can you squirt something "yummy" near it to trigger a feeding response and see if it opens up then? Generally, you should leave a coral alone when you put it into your tank for a while to let it adjust - put it where you think it will be happy and then don't move it. Acans don't need to be too high, and very high flow won't make it happy, so get those missing test kits and see what the rest of your parameters are, because where you have it should be fine.
I spot fed it last night, and this morning there was no change. So I moved it to a different location where the flame doesn't hang out, hopefully that works. And I put up an algae sheet at the top, thanks to a fellow reefer. We will see and keeping fingers crossed.
i was about to ask it look like its being picked at thats how one of mine looked when a cleaner shrimp was feeding on it every night, move it to a safe place and leave it alone it will heal
If the flame has developed a taste for this coral, then I'm not sure that moving it will help so much, but you never know. Did it look just like that when you bought it?