I have either mustard algae or pollen showing up on the bottom of my pool. After doing a search on the forum and reading countless posts, I am still not sure which one I am dealing with. The spots do vacumm up very easily and seem to show up more after a couple days of rainstorms. Doesn't seem to have anything to do with sun vs. shade either. Anyway, I went ahead and shocked this morning to 22fc which is higher than what I need for my cya level(which is around 30). Should I run the vacumm right now with the pool at shock level? I was curious to see if the spots went away without vacumming while at shock levels in an attempt to determine if I have pollen spots or mustard. Seems like I read somewhere on here that mustard algae would vanish while at shock levels only to return when the FC comes back down? How long would that likely take? I shocked about 3 hours ago and so far there has been no change to the spots.