Microscopic bubble algae

[dannobiocube]

Pest Algae help. I have an microscope algae taking over my one year old tank. To the eye it forms loose green mate that can be easily brushed away or vacuumed. But it quickly returned a few days later. Under a microscope it appears as very small spheres. Any idea what I’m looking at? At first I thought it was cyano but chemi clean didn’t touch it and after looking at it under a microscope it’s not cyano. My parameters are as follow.

Nitrate 17 ppm
Phosphate .04 ppm
Ph 8.2
Cal 420
Mag 1350

Thanks for any help

Dan

 

[lapin]

The first picture looks like green cyano. I have some. Not sure what it looks like under the scope