Last week my Royal Gramma stopped eating one day, upon a close inspection I saw small white dots on his tail and pectoral fins. After a day and a half with no improvement I went out and got some coppersafe. I have been following the directions and keeping the level at around 1.5ppm CU. My question is how long should this level of copper present? A week or two? The directions on the packaging and bottle say nothing about this. Thankfully this happened while he was still in the QT. I plan on keeping him in there an additional 4 weeks AFTER the end of the copper treatment. But I just dont know how long to treat him with copper for.

If a parasite goes through an egg- or cyst-laying stage, one should treat for at least 3 weeks.

Well I'm assuming (key word, assuming) that what my royal gramma has/had is marine ich. I haven't seen anymore spots on him. I just wanna be sure I eliminate the disease while at the same time not exposing the fish to more copper than need be.

So, how long has he been spot-free? Is he eating again?

He went spot free after two days of treatment. He has been eating since the day after adding the copper. Today is his 5th day being treated with coppersafe.

As long as he's staying healthy and eating well, I would finish the treatment. The worst thing would be to carry over the cysts into the tank and infect all the fish!