What salt brand are you using

I don't have a salt tank yet but I have been looking into prices and comparing brands.

Instant Ocean Sea Salt seems to be the best priced as well as best reviewed so that is the brand I will likely go with when I get one set up. It is only $13 for a 50 gallon bag.

What about using salt in QT tanks as preventative measures for unknown pathogens/illnesses? What amount of NaCL would you use in the tank? This wouldnt be a salt bath of course, but just a constant salinity until the QT period is gone.