Is this Diatoms?

[AquaPin]

Looks like Dinos to me. I would suggest doing some research, but best results I had were achieved by doing the following:

Lights out for 5 days (complete black out except for 15 minutes a day for feeding)
Raise pH to 8.4 or greater
Using Hydrogen Peroxide
Filter Sock
Run Carbon for toxins
Water change 30-40% after lights out