So I had an algea bloom a week ago and slammed it. There was small patches of algea growing on bottom and walls. I brushed it. Its been staying clear for a week at normal chlorine levels but the same spots I brushed had come back and look dirt, green, yellow color. When I brush it, it looks like dirt getting brushed. How rare is Mustard Algea? My chlorine levels have been going down like normal. Should I bring it up to mustard algea shock for a day and brush it?