No you shouldn't need water changes in your DT, keep your shrimp fed turn your light on and off business as usual need to keep your bio filter going. Depending on the size of your QT you may need to do a few watch your water quality. One fish probably not a big issue. Oh and don't cross contaminate during entire process that's nets, test tubes, cups, algae scrapers ect. Even your Hands, where gloves is best two pair one for working in QT one for working in DT. Ok I think by now you think I am crazy but trust me if your diligent you will rid yourself of this and with proper QT it will never be a problem again.