Hey Bearclaw, I've got the same problem on my pond. I've done a little research, but havn't picked out a plan yet. I'ver heard everything mentioned from the others in your post. Be careful about raking it out. I've read that this causes the spores or something in the alge to release causing new growth so I'm not sure if that works or hurts. One resource I get info from is a web site called Pond Boss. You may already know about it, but you can read till your heart is contend about Pond Managment.