Help with microscope ID of red dusty stuff

[bBurn18]

Hi everyone.

Quick summary - had Large cell Amphidinium in my sand bed. Has taken forever (6 months) but I cant find them anymore and no more brown patches. Been free of them for about a month. I lost a lot of coral (mainly sps) and was a bit confused because I thought LCA weren't so toxic.

For months there has been some bright red spots on the very top rock (closest to the light, with good flow). The snails avoided it and the spots would not disappear at night. They could not be blown off with a turkey baster. So finally yesterday I cut off a piece of the coralline which its growing on and decided to check it out under a microscope. I'm hoping these arent coolia dinos but that would explain the high toxicity and coral losses...

Please help me ID whatever this is. :)

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Here is a normal pic of the location. These spots move (get brighter, darker in various spots) over time but they do not go away at night.

These two pics are under 500x magnification (10x, WF25x, 2x lenses)

These video are from 2000x magnification (40x, WF25x, 2x)

This one looks like diatoms.
Not sure what the bunched circles are?

What are these large brown circles? Seems like it could be coolia?

 

[taricha]

Here's a screenshot from one of the vids. the larger more golden cells toward the center of the mass could be a round dinoflagellate.
The smaller, redder, spheres are something else. One of the none-of-the-aboves that we run into in the hobby sometimes.
@Dan_P check out the nice shell/cyst-like structure on those.

One of the other videos shows mostly common diatoms.

 

[Dan_P]

Here's a screenshot from one of the vids. the larger more golden cells toward the center of the mass could be a round dinoflagellate.
The smaller, redder, spheres are something else. One of the none-of-the-aboves that we run into in the hobby sometimes.
@Dan_P check out the nice shell/cyst-like structure on those.

One of the other videos shows mostly common diatoms.

I couldn’t view the videos. Thanks for the screen shot.

The encysted cells might be a cyanobacteria.

 

[bBurn18]

I couldn’t view the videos. Thanks for the screen shot.

The encysted cells might be a cyanobacteria.

Here is another interesting video of the same specimen but these have some kind of moving transparent appendages. Video and screenshot attached

@taricha

 

[Dan_P]

Here is another interesting video of the same specimen but these have some kind of moving transparent appendages. Video and screenshot attached

@taricha

I can’t view the video on my iPad. Rats!

Anyway, the waving filaments could be a cyanobacteria, like Spirulina.