

Just for reference, here is day 1.
And here is a shot after roughly 10 days. I just realized looking at the photo that my dersa fell over, lol, someone has been digging around him.
Nothing was changed besides dosing the tech m. No water changes, didn't pull any algae out, did not touch the tank besides feeding and moving a few corals. I did noticed it ****ed off the leather and my duncan coral a bit, and my birds nest but nothing else was effected in the tank.
The toadstool looks ****ed and the monti's bleached,unless the lighting somehow changed. the feather duster also looks happier in the first picture.
That looks more like an up & running (young) display tank. Physical removal, a hydrogen peroxide treatment & GFO is the way to go IMO. BTW I can't confirm its bryopsis from those pics - a good close up would confirm it.
If you're talking about just a tank or tub of live rock with no coral, bleaching the rock will be the best method. If done right it will zap the bryopsis completely. Forget the Tech M in this case. Keep in mind that bigB can hitch hike in on a clam shell, frag plug, exposed coral skeleton, perhaps a snail or hermit shell & equipment like pumps. It can also come in on sand & possibly water from an infected tank. You'll never have a better chance to avoid it than in the beginning. Good luck.