Christopher wrote:

Do you have a link to a picture of BGA, I'm interested in knowing what it
looks like, since everyone seems to deem it the SATAN of algaes. Also is
there nothing that will eat it, and did you ever consider UV steralization
to retard the spreading of it?

BGA: Blue Green Algae-actually not algae at all, but Cyanobacteria. Usually
blue-green in color, it grows in sheets, ranging from small sheets that just
cover a leaf or a piece of gravel, enough to cover a leaf, to large sheets that
cover entire plants, sections of gravel or planes of glass. It is easily removed
by vacuuming, scraping or rubbing with your fingers. It stinks when you pull it
out into air.

BBA: Black Brush Algae-this is probably the satanic strain you are referring to.
Black, dark grey or dark green in color. Short tufts of hairs, up to about 1cm
in length. A big tuft can look like a pom-pom, or like a black dandelion seed
cluster before a kid blows on it. Does NOT remove easily-nearly impossible to
remove from plants withot damaging them.

Here is the best visual reference to algae types:

http://www.aquaticscape.com/articles/algae.htm