dying short tentacle plate coral

[margaritaville]

I purchased a green plate coral about 3 weeks ago, all has been fine. Yesterday I was home during the day and noticed a patch of white die off?
And last night It didnt fully come out when the lights were on. My 3 yellowhead jaw fish did recently move into a new home on the side of the tank where the plate is, wondering if this could have any reaction to it.
Also found what looks like a baby brittle star, about 2" and added about 15 new red/blue leg hermits a week ago.
Tested water last night as well and everything is great, Nitrates are as low as I've ever had at 5.
Have had a problem with those damn japenese beetles getting into my house and in my tank, having to net out 5-10 a day. Could these be killing the plate?
Im at a dead end with answers, any help would be great
Thanks
Eric

 

[bkv1997]

First off do you have it on the sand bed? Do you feed it from time to time?

My first guess from the details provided would be the jaw fish dumping substrate on it when making their new home.

 

[margaritaville]

Yes its on the sand bed, But the jawfish arn't really spitting too close by it.
Yes feed with cyclops mixed with my DT"s plankton.

 

[margaritaville]

I want to say it looks like something might be eating it! because it was fine then just one day it had about a square inch of die off. Anyone know of what might eat it?

 

[bkv1997]

I would check it out at nigth and see if you catch anything nibbling on it, but I don't know of anything off the top of my head.

 

[jhnrb]

Hard to say what caused the problem, if you have any corals that wax off, the shedoff it landing on the plate can burn it, a sting from other corals, something eating it, etc. hard to say. could have been damaged prior to introduction. did you make sure no air got under the plate when introducing it to the system. good luck hard to say. may be a gram negative bacteria infection now, hard to say. best of luck. bk had a good suggestion, check it out at night with a red light and see if something is dinning on it. keep us posted. if i think of anything else ill post here.

 

[margaritaville]

Well seems like the plate is doing better. no more die off and it expands much more from time to time. It did look like it shed a sort of mucus layer a week ago.

 

[jhnrb]

If you have softies that wax off, could have been the wax off contacted the plate which would have burned it. if the mucus was from other than the plate it probably burned the plate. glad to hear it seems to be doing better.