Good morning fellow reefers! I’m fairly new to the hobby (7 mths) and have a question about my hammer coral. I’ve had it for 6-7 weeks now and it’s always seems happy, It still appears happy and inflated during the day, but now has this tentacle void in the centre of one of the 2 heads whenever open. It this something I should be worried about? My parameters are all good and stable … calcium is low, but I’ve been gradually bringing it up for a couple days. Picture and short video below. Thanks in advance for any insight or advice.