In dire situations (i.e: ammonia spike), I've done as much as a 75% PWC
to save the fish. That was, however, dire circumstances. Your diatoms will go away as your tank ages. Other types of algae blooms may actually be enhanced with water changes depending on the chemistry of your source water (high nitrates will aid some types of algae growth). Do you know what the source of the offending particles is? My first thought is to say that you remain patient and continue to perform normal water changes.