HELP: Weird white things on my hammer coral

[smhray]

I noticed that my green purple tipped hammer was not really opening as much over the past 3-4 days. This was all under the blue light though I have been out during the day a lot recently and haven’t been able to get a really good look at it during white light time. I have the stock fluval evo led light. When I took a closer look I saw some white things coming off it which all my other hammers that were opening up huge didn’t have.
Does anyone know if these white things are causing the coral problems? Or maybe something else might be causing it to not open fully?
Here’s a picture:

 

[Ron Reefman]

Maybe a fine algae... or some kind of hydroids?

#reefsquad

 

[TriggerFinger]

Agree with hydroids. They can be removed with a toothbrush