Small white specks crawling on algae?

[Tony R.]

I saw some hair algae growing and thought I'd let it run its course but on further observation when all flow was off I saw them moving independently. See the gif below. Macro shots also below.

About the size of the tip of a ballpoint pen.

 

[Tony R.]

GIF of pests

 

[Tony R.]

GIF of pests

Update since the time of posting and revisiting the tank I found my cleaner shrimp dead.

My tridacna clam seems irritated by the pests as well. Everyone else is behaving as usual.
(Clowns, pistol shrimp, goby, conch, corals)