If you have a UV, you can put the plants in a bucket and run uv for about 30 seconds, change the angle and repeat. Don't exceed 2 minutes for a plant, and don't stay in the room with it running. There will be a little dieback of the plant from sunburn. Peroxide to kill it from the plants and install a UV inline in the filtration system is another option. The strands that live will remain, but it will have a hard time spreading. If it's Blackbeard cranking the CO2 could work, if its hair algae, I don't think it will work. A Siamese algae eater would love a shot at that. But be forewarned they grow quick and done can get a bit aggressive.