I know this has been discussed before but I was wondering if we could re-visit the subject do to my memory condition (CRS). The birds drink out of my fountain so I'm using a cleaner that's wildlife safe, you add a capful once a week. Problem is, it doesn't work. I drain and clean it and at one week its already covered with algea by week two I have to clean it again. Is this normal or does anyone have any suggestions?