Has anyone used this product for Ick ( white spots )? I've checked some o the reviews for this and I've seen 15 out of 15 recommends using this. My Blue Tang and other fish now have ich. I'm worried I may lose them all I want to stop this soon. If quick cure does not work I'll try copper next. I just don't know how to administer it? Any advice?!?!?!?!?!