Algea identification microspope

[Waterbourn]

My sandbed is turning a brown color. I just used chemiclean for a cyano problem and it cleared it up wonderfully. Then a couple weeks later the sandbed started turning brown I thought cyano came back and tried chemiclean again but not touched it

Under the scope at low mag I see these purplelish circles all one the pieces of sand under high mag there are circular to oval and they move/swim at a pretty good clip. High mag pic attached

What is this?

 

[mcarroll]

No pic showing yet, but it sounds likely to be dino's.

See if this helps you decide:
Dinoflagellates – Are You Tired Of Battling Altogether?

 

[Waterbourn]

Pic doesn't want to post. If doesn't work this time I will post after work.

 

[mcarroll]

Pic doesn't want to post. If doesn't work this time I will post after work.

That looks like a dinoflagellate to me.

Start following the guidance on that dino thread I linked (no GFO, no carbon dosing, etc, etc) to the extent it makes sense (ask questions as needed, of course) and consider posting your pic up in the dino thread I linked to get more eyeballs that are better at ID than I am. Folks can probably tell you the specific kind so you'll have a great idea how to proceed.