Plate coral oddity

[toadfarm]

Hello - I just noticed that my plate coral, about a month in my tank, has a white milky substance on exactly one half of it. Not sure if another coral stung it or a crab walked over it. Pics attached. Ever see this before?

 

[vetteguy53081]

Increase water flow towards it- NOT AT IT and see how it responds.
Also check and verify:
Salinity
Ph
Alk
Ca
Nitrates

Moderate light and water flow