Any potential reason my indo is dying/dead

[Reef Wizard]

Can someone weigh in thoughts of what happened to my indophyllia. This guy was once dinner plate size Before and after below. I did go to look and he has sand down in his mouth what left of the mouth there was. and I flipped him over and he has a hole through the bottom of his shell.

I found what I think is a bristle worm see pic below attached to the underside of him. I dont think the worm caused it he was just feeding on it due to it decaying.

Should I attempt an iodine dip even if the mouth is completely gone?

ph 8.2
alk 8.4
cal 415
mg 1410
Nitrates 32
Phos .8 (normal for my tank)

 

[Naso180!]

Iodine dip cant hurt. Im sure you're right on your assumption about the bristleworm not being the cause. Potentially a boring worm or moluscs that caused the hole. Is the hole completely through to the top? Have you been actively feeding the coral?

 

[Reef Wizard]

Iodine dip cant hurt. Im sure you're right on your assumption about the bristleworm not being the cause. Potentially a boring worm or moluscs that caused the hole. Is the hole completely through to the top? Have you been actively feeding the coral?

So the mouth looks receded/gone and underneath on the stony section of the coral there is a hole. It doesnt appear to go through unless it goes from there to the mouth opening

 

[Reef Wizard]

So I Dipped the indo today. Any have input what that on the bottom might be I have not seen it before.

His flesh is going away alot. I hate to lose him :/