I had a huge outbreak of Bryopsis a couple years ago. I found you can't suck it up with an airline tube the way you can with hair algae, because Bryopsis is stiff - it's not flexible enough to go up the tube. Heck- you can grab ahold of Bryopsis and pick up a piece of live rock with it - the stuff is tough. I got rid of mine in a 55 gal by finding the right Yellow Tang. Put a few wads of the Bryopsis in a baggie, and take it to your LFS. Drop it in their tank of Yellow Tangs (with permission of course), and watch closely for the one or two that eat it. Some will go for it, some will ignore it. Buy/borrow the one that eats it. Worked for me. It ate it all in a few weeks. I took back the Tang, and now I keep two urchins grazing at all times.