What are these round, donut like shapes ?

[Idech]

I have been dosing sodium silicate for 4-5 weeks to get rid of prorocentrum dinos. I haven’t seen any in the sand for a while so today I checked under the microscope.

I couldn’t find a single dino in 3 slides (maybe a single one) but I noticed a few tiny specs flying up and down and some other worm looking things eating the dark spots. Which I figure are good micro organisms.

I also saw many perfectly round spots that look like donuts and I am curious what they are. You can see them in the blue rectangles. Also an example of a large dark spot that I presume is a clump of diatoms.

Tank is 2 years old. Any idea what those are ?

 

[Reefering1]

Beats me. The last pic looks like the moon. Bump

 

[Dan_P]

I have been dosing sodium silicate for 4-5 weeks to get rid of prorocentrum dinos. I haven’t seen any in the sand for a while so today I checked under the microscope.

I couldn’t find a single dino in 3 slides (maybe a single one) but I noticed a few tiny specs flying up and down and some other worm looking things eating the dark spots. Which I figure are good micro organisms.

I also saw many perfectly round spots that look like donuts and I am curious what they are. You can see them in the blue rectangles. Also an example of a large dark spot that I presume is a clump of diatoms.

Tank is 2 years old. Any idea what those are ?

No diatoms in sight, in fact, nothing living in sight. The perfect circles look like air bubbles or oil droplets. Physical objects most likely.

 

[Idech]

No diatoms in sight, in fact, nothing living in sight. The perfect circles look like air bubbles or oil droplets. Physical objects most likely.

Could they be microbubbles ? I have lots of those because of my internal skimmer.

 

[Dan_P]

Could they be microbubbles ? I have lots of those because of my internal skimmer.

I think micro bubbles would appear very large under the microscope