I've been using aptasia x successfully. they key is to be on the offense and stay on top of them. I'm beginning to wonder if they will every be gone completely but i'm winning the war. shut your flow off and get what you can in one sitting and repeat every week or two. let it sit on them for 10 minutes or so before turning flow back on. i bought a couple monaco shrimp to try and help new ones from forming but i havent seen them since they went in. if you are worried about it affecting your corals, it didnt affect anything in my tank, LPS, SPS, fish etc... i will admit i was scared when i turned the water back on and created a snow storm of chemical the first time!