I've been investigating an unexplained fish death and I noticed something I have never noticed before. Very close inspection has revealed thousands of very very tiny somethings adhering to the inside of the glass on all sides. Invisible unless you are right up within a couple inches of the glass. They are round, whitish, translucent, and about 1/2mm in size. They wave gently in the current. They are everywhere. Not sure if this is a threat. Anyone know what they could be? They are far too small to photograph, unfortunately. Hopefully, this is just a strange-looking algae bloom, or a normal microflora/fauna, but I just don't know. Any input would be appreciated. Thanks I really don't want to lose any more juvenile angelfish!