If you have access to one, an inexpensive SeaChem ammonia badge is good to have in a QT that has no biological abilities. Prime is also good to have as an ammonia reducer for QT. Don't exchange anything between transfer tanks not even wet hands or a towel, the next tank in waiting needs to be sterile. Every time you transfer, the number of ich parasites goes way down. In theory it works.
As Ziggy said, when you have the opportunity stock some Copper Power and Prazipro. I think you said you already had a copper checker.
It looks like you've caught it early, good luck and keep us updated.
