Digitata Getting Chewed By.....what??

[Reefgrrl]

Over the past several days I’ve seen these white bands growing. Started as one white spot on one branch that blew off with a turkey blaster. Now this....growing slowly but definitely growing. Too bad I didn’t take daily photos, but I will now. Any ideas? I’ve had white coralline suggested. I’ve looked at it with a magnifying glass but not seen any nudis (have had these, know what to look for).

I’m considering removing it, trimming it back, and dipping it. But being an SPS I’m reluctant to go overboard on the dipping. ‍ Thank you for looking.

 

[kapelan]

that's bleaching.
Red Digitata pretty easy coral it needs just good light to survive.
Problem most likely with water.
Ca,Mg,KH - should be retested. If the result is OK you will need to get new tests - probably existing does not work anymore.

 

[Luke.]

IMO looks like rtn to me ..

How long have you owned the coral for ?

If you’ve seen it in the past 2 days or so , I’d give it 4 more days before it will be all white if it’s rtn

 

[Copperkills]

RTN and STN generally start at the base, not in random spots on a stalk. Are you dosing alk closeby? Could be Alk burn.

 

[Copperkills]

Here is a pic of an acro with alk burn

 

[Copperkills]

https://www.advancedaquarist.com/2016/9/aafeature

 

[Luke.]

Maybe a fish nipping ??

 

[Salty Cracker]

My guess is alkor kalk as well. I've burned a couple like that in my day. Check parameters and likely it will bounce back (digi is pretty hardy). If not, you can likely get a few pounds of digitata off someone here for a pack of gum.