If I had a fish store I would advocate for QT. As I said, use a flyer with QT instructions. Set up a QT in your store for "show and tell". Sell QT setups, etc.
However, this doesn't address your store's problem with having chronic ich problems with fish. Again, look at your supplier.
However, this doesn't address your store's problem with having chronic ich problems with fish. Again, look at your supplier.