Are these what's killing my Acan's?

[Leadfooted]

I thought it was new lighting (still might be), then my Potter, but lately the hermits have been all over the acans.

I have several other colonies on the rocks that are doing just fine. PAR's good and all LSP and SPS thriving, all but these

 

[ChiCity]

If you're feeding your acans, then yes it's a possibility the hermits are ripping food out of them...

Usually though, hermits don't really mess up acans unless there's something already wrong with the acan, then the hermits are capable exacerbating the condition

 

[erk]

The hermits are probably attracted to them because they smell dying flesh. I've seen my hermits eat dying coral flesh, but leave living flesh alone. Did you acclimate the acans to your light? Also, did you ensure you alk, Ca, and Mg are all within acceptable levels? I always noticed my LPS receding when Mg dropped below 1280ppm.

 

[Leadfooted]

Mg are all within acceptable levels? I always noticed my LPS receding when Mg dropped below 1280ppm.

hmm.. Well, actually I've noticed my MG levels dropping ever so slowly and I just checked and it's now dropped to 1160-1170. Usually my tank hung around 1240-1260 with no issues. Wonder What's causing the drop.

I did acclimate but possibly not long enough for some. I did lower the rack just in case as you can see.

Currently ....

 

[erk]

I'd try to bring the Mg up and give them a week to recuperate. In my experience, if I catch the low Mg and correct it quickly, then everything rebounded. But if I put it off for too long, my other corals would follow a week or so after the first signs. Sadly, I learned how important stable Mg is for the health of a reef tank the hard way.

 

[ChiCity]

I'd try to bring the Mg up and give them a week to recuperate. In my experience, if I catch the low Mg and correct it quickly, then everything rebounded. But if I put it off for too long, my other corals would follow a week or so after the first signs. Sadly, I learned how important stable Mg is for the health of a reef tank the hard way.

Mg is the wedding ring that keeps Alk and Cal married together in holy matrimony

 

[Labridaedicted]

+1 to the hermits not being the cause. They will eat the slime produced from stressed corals or dead tissue. They won't bother healthy tissue (unless it's a snail). Mg could be the cause, but I'd be more likely to go with light.

 

[ahiggins]

Side note for hermits-they may be digging food out of the dead skeleton. Ive seen them do that before. They raking their shell across the flesh may be irritating them and exacerbating the underlying issue.

 

[Leyth]

I've had acans do that when I've placed them in too much light. Really they're not unhealthy, they just look like it. The whole reason they expand and get puffy is to have more surface area for photosynthesis. If they don't need the light, they won't expand.

Not saying that's what is going on with yours, but just something to consider reading into or checking out.

 

[Dabcrusher]

 

[Dabcrusher]

I just looked at mine and it has eaten a little blue ledges hermit crab