I see this post is old, but my battle with ick was a one time event until making friends with a real UV sterilizer. Had poor luck with the "toy" sterilizers like green killing machines. I also had invertebrates in the tank and did not want to use copper, so stuck with Artemiss and Herbtana at the lowest recommended dosage. Be aware that to target ick, the flow through the UV must be much slower than if just killing Algae. And for the record I have had good luck with a coralife tutrbo twist, but if you value your tank and its inhabitants I would recommend something more substantial like a unit from Aqua. Got mine from All things aquatic for a super price!