It could just be hair algae starting to take over with the nutrients elevated in the tank. Check your parameters to be sure. If you can get a pic of that stuff under a microscope, that would help with identification as well.
Looks like an algae and bacteria combo. Agree with idoc on nutrients levels. Also check both Phosphate and nitrate for elevated levels.
You can reduce white light intensity a little. Add a pencil urchin and some Cerith + Astrea snails when you get a handle on this. Add 1.5ml of liquid bacteria per 10 gals daily for 10 days and 1ml of hydrogen Peroxide per 10 gals at night.
IF no improvement within 5 days, consider using liquid Vibrant but dose at 80% of recommended.
I have some shrimps... it is ok to use h2o2 with shrimps?
Also my phosphate is 0.02 and nitrate is around 5ppm now... I dont think this is the problem cause I got this when I was 0 Nitrate and 0 Phosphate while dinos was taking over