Your hammer, from what I can see in the picture, seems like it's still got a chance - it's just getting a bit too much direct flow, in my opinion. I'd suggest trimming off the dying tissue and giving it an iodine-rich dip. I've noticed that if they don't get enough light, the overlapping membrane tends to recede.
Wall hammers, or any wall euphyllia for that matter, require a lot more TLC when you first get them. Shipping can be pretty rough on them, and people often make the mistake of blasting them with too much light and flow right off the bat.
Make sure your phosphate levels aren't too high, and your nitrates are in check as well. When you first get one of these guys, especially if it's been shipped in from overseas, keep an eye out for brown jelly or white jelly. I'd recommend dipping it in an iodine-rich solution twice a day and gently removing any dying or necrotic tissue.
After that, put it in medium lighting - around 250 PAR - and keep the water movement active but at a low velocity. I've had pretty good luck with maricultured or aquacultured specimens, personally.
This isn't my first wall euphyllia, by the way - I've been keeping these guys for about 15 years now. Give it a month or so, and the tentacles should start to get "sticky" again, which is a good sign. At that point, you can start feeding it bits of mysid shrimp to give it a boost.
Hammer coral showing skeleton
Re: Hammer coral showing skeleton
I'm inclined to agree with the others, walls do seem more finicky when dealing with tissue separation compared to branching types. I've found that when dipping, adding some peroxide to the mix can be beneficial - try a 50/50 mix with water. Only dip for 10-15 seconds, then rinse and let it rest in the tank.
Re: Hammer coral showing skeleton
In my experience, once the tissue starts separating from the skeleton, it's usually game over. The damage is done, and there's no going back. It's like an open wound, an entry point for all sorts of pathogens and unwanted critters to start wreaking havoc from the inside out.
Re: Hammer coral showing skeleton
Thanks for the input, my own experience with walls hasn't been great either, which is why I asked in the first place. I think I'm gonna stick with branching from now on, plus I'll make sure to get non-wild ones.
Re: Hammer coral showing skeleton
My experience with branching hammers has been smooth sailing - I've got one from Indo and two from Australia, all wild, and they're doing great. What caught me off guard was when I came home late yesterday and saw the Indo hammer trying to get a little too cozy with one of the Aussie hammers, so I had to intervene and move it a bit further away to keep the peace.
Re: Hammer coral showing skeleton
I think it's more about the nature of the coral itself rather than walls being inherently more prone to damage. With branching, you've got separate heads that aren't connected by tissue, so if one gets damaged, you've still got others that are unaffected. Walls, on the other hand, are all one big piece of coral.
Dreamon7 makes a good point about Euphyllias being easily damaged during shipping. If they're not properly protected, it can be a real issue. And the worst part is, the damage often doesn't become apparent until you've already brought the coral home. I think a lot of people, especially when they're just starting out, don't know what to look for in a healthy Euphyllia. It's not until you've lost a few that you start to realize the importance of checking how far the tissue extends down the skeleton and making sure everything is inflating equally. Once you become more discerning about what you're buying, I think your chances of success increase.