I'm not flexing anything other than sound, logical advice in regards to sustaining the natural salinity levels in order to alleviate UNNECESSARY stress.
Medicating and dosing does not resolve issues, it merely masks them, much akin to putting a Band-Aid on an Arterial wound.
Also, as you've pointed out, if there is so much Copper being used along the way, then there should not be a need for it in the end. Conversely, if healthy livestock is bought from high-quality wholesalers that closely monitor and regulate how their specimens are captured, then there should not be a problem.
Out of 3 pages filled with input from many LFS owners and operatos, I've yet to read a single post in regards to using Garlic to get rid of Ich, yet we all know that it not only works, but aids in building immune systems. It was mentioned that any Tang with "Powder" in the name will be an Ich magnet, but again, Garlic feedings have never been mentioned.
Furthermore, being that they are aggressive cannabalistic scavengers, Damsels are about the worst fish that an LFS could ever sell, but they do so because they are cheap and colorful. Very few serious reefkeepers will ever have anything to do with them, as they are a beginners fish, that carry a ton of diseases (
which is why you'll ALWAYS see a few weaker ones getting picked on). Hell, 98% of the Damsel posts here and elsewhere are in regards to all of the creative ways to get rid of the mean little bastards!
I never owned or worked at an LFS; but I do maintain reef tanks, run the local reef club, consult on specific issues, have designed and/or re-designed numerous reef systems, and have invented reefkeeping products that are currently on the market.
Basically I'm just a nobody, but a nobody that knows I'm doing.
-Tim