Heres an idea, quit chasing PH, and quit jacking other peoples threads, just sayin!
Wasnt this thread about a QT issue and developing ich while in QT? How did this end up talking about NeonNate's... I mean GreenNate's PH. LMAO!
Now, back on subject. What temp do you keep your QT tank? I reccomend a slightly elevated temp in QT, I keep mine around 82. The higher temp helps stop the life cycle of the crypto (real name for saltwater ich). Also, when having fish in QT I reccomend small, but daily or every other day water changes. I myself use a 40 breeder as a QT and when housing fish I do a 5 gallon water change every other day, I feed heavy with algeas and garlic and I DONT USE COPPER!
Believe it or not, I would reccomend hypo before I reccomend copper, and if you use copper plan on doubling the QT time as you get the water back to normal perameters. Reason is this, copper destroys the fish's immune system and it can get to a point where only the copper in the tank is keeping the fish healthy, so you slowly have to remove the copper fomr the water so the fish can build its immune system back up. If you added it to DT right after QT in these conditions the outcome will not likely be pretty for the fish. Ive actually killed an ich outbreak on my 180gal wihtout the use of any chemicals, without the loss of any fish or corals in the process, simply by a hearty diet and elevated temperatures.
I wrote up an article a while back for my own reference on my dealings with crypto, I was gonna post it, but Im my own worst critic, so Ive kept it private. Id be happy to send you a PDF copy if you would like to read about my personal methods and expericnes, it may help, it may not, would be much easier than posting it all here.