Dinoflagellate ID Help! Microscope Pics Inside

[BenitaSolo]

I’ve been plagued by a brown algae that covers the sand bed rapidly for about a month now. After ChemiClean didn’t help I borrowed a microscope...
These pics are what we uncovered
I don’t notice that the algae dissipates at night.

Are these Coolia Dino’s?

 

[duberii]

They kind of look like rotifers, which are a good source of food for fish fry.

 

[Maritimer]

Or possibly diatoms. Diatoms utilize silica for their shells, so they're common in new tanks, but can grow in older ones as well. Pretty sure I have some on the sunnier side of my sandbed, they've got a kind of "granular" look to 'em, not the "snotty" strings of dinoflagellates.

~Bruce

 

[dwest]

I’ve been plagued by a brown algae that covers the sand bed rapidly for about a month now. After ChemiClean didn’t help I borrowed a microscope...
These pics are what we uncovered
I don’t notice that the algae dissipates at night.

Are these Coolia Dino’s?

I don’t think they are dinos. Do they move?

@taricha would know.

 

[BenitaSolo]

I don’t think they are dinos. Do they move?

@taricha would know.

They look just like what is in this video. Yes they move around. They come back quickly after I syphon them out. They are brown and stringy similar to the look of cyano.
Nitrates are .1, po4 is 0.00 in the normal hanna phosphate checker. I have a ULR coming soon.

This tank is a year old but 1/2 or so of the rock and livestock came from a tank of mine established for 2.5 years prior.