Help with possibly dinos

[AZ_Reef]

I was battling with dinos last two months. It looks like they are gone now, but noticed a lot of bubbles and brown stuff on top of sand. I bought a microscope but don't know how to use it. So how do I put them under microscope? They are very fine.

 

[lapin]

 

[taricha]

nice! some good microscope techniques there.
In looking for brown dino/diatom/cyano etc, usually taking a pipette and sucking up a droplet of brown or bubbly or stringy material will give you an idea of what organisms are there.
too much sand/debris and you'll see nothing. Slide cover not always necessary, I just pop one on if I want to go to high power.

 

[AZ_Reef]

Thank you. Very helpful video.