diatoms

Had anyone seen this article? https://reefbuilders.com/2020/05/11/dinoflagellate-aquarium-treatment/ It in short shows that raising your tank to 82 degrees for a week will kill them all off with no effect on the tank. Still seeing if this affects multiple species of dinos but it's showing...

30 gallon tank, set up for about a year, just started having brown algae (diatom?) problems a few months ago, most likely due to using tap water. I have been using RODI for more than a month (I learned my lesson!), but the brown algae isn't really going away, it is still covering all my sand...