I think you may have more than one species given the different shapes I see. Research Ostreopsis ovata as one distinct possibility.
Many suggestions on R2R and a simple search will give you enough information/opinions for several days reading, lol. One key from my experience is to try 3-5 day blackout, add UV sterilizer and increase biodiversity with some product like Dr. Tim's, Brightwell's Microbacter 7, etc. Good idea to syphon out as much as you can and depending on size of sock you would syphon into ( if I remember correctly, I used 5 microns for catching dinos) you may want to return water to tank.
Thanks for the reply!
I'm trying to upload a video as well.
I have tested a UV sterilizer but I saw no difference (Deltec 39w on 620l tank). I have raised No3 to 5-10 and Po4 to 0,10-0,12 but no difference.
I'll read a little and I'll see how I proceed...
Sorry for your Dino's! I promise to fire the lab back up but it will take some time to incorporate my business with this.
Those guys will lay dormant if you stress them enough so keep that in mind while you make a plan to deal with them.