It could be hair or some other algae. Hard to tell with all the blue light. I also se what look slike a bit of cyano (red stuff). If the tank is new perhaps some critters that will feast on the algae might help
There’s dedo el tu some red hairs. I do have 4 turbo snails but they don’t seem to be interested in munching it down. The tank was restarted about 3 months ago. I did get a BRS mini reactor going over the weekend with carbon and GFO.