I have had this leather for 2 years. It has grown fast from a mini frag to a 6" in diameter thru the years. every once in a while it retracts to remove the algae build up and opens a couple days after. I am worried, It's been past a week and it's still not cleaning the algae from its's surface like it usually dose. Is there anyone who has seen this and is it normal?, Is there anything I can do to help this coral?. I ruled out water parameters, They are in spec, or the other large leather I have would do the same along with it.