Another Copper Treatment Question! Adding new fish to QT already under treatment?

[howdy20012002]

I personally have my quarantine tanks all at around the .5 level and add fish to them constantly with little loss.
I do lose some fish, but lose is expected and usual when bringing over boxes of fish from overeseas so it is hard to know what exactly was the cause of death.
I certainly do not have more losses now by adding them directly into the systems that are at .5 than previously when I only treated when I noticed signs of disease.
This being said, it also depends on the fish.....some fish have less tolerance.
What you could do is drop the level a bit lower - say .30 - .35 this will be less hard on the fish.
At the same, as far I understand it, will still be sufficient enough to defeat ich and marine velvet.
I believe that cupramine is typically considered effective at the .25 mark, they just have the .5 to ensure that you have a safety parameters on either side.
hope this helps
good luck
Neal