Originally Posted by bessycerka
Corallife deep six swing arm type hydrometer.
The swingarm hydrometer you are using is useless. Do not attempt to do hyposalinity with this instrument; it is so inaccurate that you could end up doing more harm.
Copper is a good all out treatment for many parasites. Stick with it. However, you have to get the copper levels to .5ppm and use a compatible copper test kit, such as the one made by Seachem. I seriously doubt your LFS administered copper treatment appropriately. The stores basically dump a few drops of copper in, no measurement, no maintenance of levels. All this accomplishes is to make the parasite that much more resilient to copper.
Test your salinity levels using a floating glass hydrometer, and throw away the swing arm hydrometer. You will probably have to go online to look for a refractometer, however, its well worth it to have one.